Plaguelords/Units 1.03

Racial Tag
There is no specific racial tag for the Plaguelords' units and most of them do not actually have a race classification at all - making them immune to all racial slayer skills and abilities. However, there are still a few units that do borrow a racial tag from the other races (Human and Undead) and most of their un-categorized units are immune to Disease. Some of which actually have double immunity to Disease (a specifically coded immunity along side an immunity granted through either their race tag or by being a Disease bearer themselves).

Zombie - Undead Builder
The Zombie is the Basic builder of the Plaguelords. Although tougher than other builders, Zombies are still fragile and weak. They can cause Disease which the Plaguelord race can abuse, punishing those who try to slay them. But really, your Zombies should be kept away from any form of combat, especially since Plaguelord Zombies do not get the Feast of Garok upgrade that the Undead get. As for building - Zombies are the worse available builder in the game, equaling Thralls for build skill, but possessing much lower movement speed.

Slime - Plaguelords' Scout
Slimes are essentially scout infantry for Plaguelords due to their high speed and surprisingly good view range. They have a chance to cause disease and deal 5 crushing damage (that can be upgraded to 20) which can stun units upon scoring a critical hit. Typically, Slimes should be spammed and sent out to explore the map and disease enemy Heroes or heavy units that they encounter along their way.

Ghoul - Plaguelords' Basic Infantry
Although they've been hit with a few nerfs in their life time, they are still much better infantry than Slimes. They can be upgraded to be faster and have better combat which makes them capable of tackling late game infantry to some passable standard, especially with their crushing type damage that can render an enemy unit all but useless upon landing a critical hit. Those aforementioned combat researches certainly play towards this. Oddly enough, they don't actually cause Disease despite the in-game help box saying they do.

Gazer - Plaguelords' Basic Missile Unit
These eyes are the basic missile units of the Plaguelords dealing 15 electric damage but at a very short range of just 4. Gazers should be spammed and force fired on a single target to deal maximum damage, as electrical attack do not scatter after missing. They can cross water which can be used to surprise enemies or even be used to target weak points in an enemy base that's positioned near a coast. They can also be used to fill towers, increasing their range and damage, but Plaguelord towers already deal electrical damage so the attack types wont change.

Bone Catapult - Siege Weapon
Bone Catapults are an inferior variant of the standard Catapult and the main reason is their range. While range 12 would be great for any other unit, for a siege weapon it's poor. However, Plaguelords are lacking in the range department, and a long range splash attack can work well for them in the form of artillery. With Slimes and Ghouls pinning the enemy down, Bone Catapults can rain death upon them, dealing the threatening damage that makes up for the lack of offense from the aforementioned units. Impressively, Bone Catapults are available at tier 2 for Plaguelords, where other races usually have to wait to tier 4 to get their siege weapons. This allows you to field them very early on where there's no much that can directly counter them. As for building destruction - Spores and Eyes of Flames can do a quicker job, but Bone Catapults with a Hydra meet shield can do the job more safely, being able to absorb common arrow attack and thus being more cost efficient.

Dragonfly - Basic Flier
There aren't any basic fliers that cause disease, so the Plaguelords had to settle for one that caused poison instead. (I never understood why Bats never caused disease.) But their poison is weak and they cost that sacred resource - crystal. It may not seem a lot at first but soon mounts up when you need to build a swarm of them in order to make them actually accomplish something. Stat wise, they're terrible. You're better off forgetting they even exist.

Spore - Plaguelords' Suicide Unit
Spores are suicide units for Plaguelords, dealing 40 fire damage (that can be upgraded) which can utterly devastate buildings. They do require a little micromanagement to perform at their best but being able to cross water allows them to bombard buildings where the enemy least expects and where it's difficult to prepare for. The upgrades that are available to them are incredibly expensive and only offer minor improvements to their damage.

Hydra - Plaguelords' Advanced Melee Unit
Hydras are very important to Plaguelords due to their good stats, resistance to piercing and slashing typed splash damage. They also cause fear, too, but that's more of an added bonus. They can handle many different units through sheer strength and sponge common archer arrows with their piercing resistance. Unfortunately though, Hydras are weak to the common slashing type damage that can undermine their anti-infantry capabilities at times. Their cost also clashes horribly with the rest of the Plaguelord race, making it difficult to produce these when you need them and without breaking your economy.

Pyrohydra - Plaguelords' Elite Melee Unit
Pyrohydras cost a stupid amount, and of resources that the Plaguelords are always in need of. Their very high combat, large damage amount and a fire typed attack can demolish buildings and infantry alike. But despite being more durable than the standard Hydra, its lack of a useful resistance and the same weakness to slashing that plagues the other Hydras can make it difficult for the Pyrohydra to stand out in any particular role. Although it can demolish buildings - it can't take common tower attacks to the extent that the standard Hydra can. With a weakness to common infantry and no common infantry resistance - it wont last long against such units. Whatever you want the Pyrohydra to do, there are other units in the Plaguelord army that are better and cheaper to do the job.

Cryohydra - Plaguelords' Elite Melee Unit
Cryohydras differentiate themselves from their fiery brethren with a rare frost type attack and a more manageable cost. Although they suffer from similar drawbacks to the other Hydras, namely high cost and slashing type weakness, they can be helpful against infantry where their frost type attack is rarely resisted and has the chance of freezing the enemy, as well as inflicting fear for further debilitate them. Of course, they need great amounts of support to function well and their high cost makes each one that much more important to keep alive, but they can be crucial in some situations that no other unit in the Plaguelord army can fill.

Eye of Flame - Plaguelords' Advanced Missile Unit
Eyes of Flames are great troops that can punish the enemy for spamming units with their fire attack that is akin to those seen from Dragons, albeit much weaker. Like all floating eyes, they can cross water to catch enemies off guard and, by being ranged, can abuse these traits to ambush enemy melee troops without them being able to strike back. However, they're quite expensive and their crystal costs clashes with a lot of other things in the Plaguelord army. Still, if you can get to field a load of them at once, then you can decimate just about everything that doesn't have "Dragon" in its name, including buildings. It's no wonder that they've been nerfed numerous times.

Wyvern - Advanced Flier
Wyverns are actually pretty good. But unfortunately for the Plaguelords, they cost gold and crystal, and a lot of it. It's that one and only reason why Plaguelords rarely use them, otherwise they would be a great addition to the Plaguelord ranks - offering a piercing attack to help keep Orcs at bay and using their speed to hit priority targets fast and relocate their position at a moments notice, greatly helping overcome the Plaguelords natural lack of speed. Before producing some, you really have to consider how much it will harm your economy to do so, and decide what is truly needed at that time.

Plague Priest - Plaguelords' General
Like with all Plaguelord units, Plague Priests are expensive and heavily compete in cost with other Plaguelord units and more. However, their amazing 40 magic type damage that can hit both ground and air units can be invaluable. These units certainly hit hard and their Plague Cloud spell can leave a lasting mark on those that try to escape them. In addition to that, with a high resistance stat and a special resistance to magic, Plague Priests can soak up just about anything an enemy spell caster can thrown at them. Their other spell "Eye of Oros" isn't particularly good considering that Plague Priests arrive very late in the game where not much scouting is required, if any at all. But if you happen to have one in your retinue, then you could make use of this spell at the start of the game - removing hidden map and spying out the enemy in advance.

Eye of Oros - Summoned Scout
The Eye of Oros is purely a scouting unit that is summoned into play by a Plague Priest. They have the highest speed in the game (except for very high level Heroes) and are highly durable. Despite the in-game help tip specifically stating they have good viewing range, there are plenty of other units which actually have a better view range naturally. But with its extreme speed, high durability and good view range, it can quickly uncover "hidden map" and not even be phased by enemy proximity. Whether you're playing a version of the game with Summon Timers, or not, Eyes of Oros will always disappear after some time has passed. Unfortunately for the Plaguelords, being summoned by their General means they wont hit the field until tier 5, where most of the hidden map would have been uncovered. However, if you take a Plague Priest into your retinue and start the game with one, then their spell to summon Eyes of Oros can be put to good use.

Swamp Dragon - Elite Flier
Plaguelords aren't particularly short of fire splash attacks, but they certainly wont pass up on the opportunity to produce a Swamp Dragon because of it. Typically, Dragons can be tricky to get a hold of, but more so with Plaguelord than any other race. Because of this, you would be forgiven for not owning one when your resources are demanded else where just to keep you in the game. Fortunately for the Plaguelords, with some clever use of their units, they can achieve near enough everything a Swamp Dragon could do for them. This is mostly down to Eyes of Flames and their ability to cross water, and Hydras / Wyverns spreading fear. Of course, a Swamp Dragon is always a great choice and if you can afford one without crumbling in the process, then go for it.

Dragonliche - Elite Flier
To produce a Dragonliche is comparable to pulling a Rabbit out of a hat. Although possible, it requires great effort and can surprise the onlookers. Due to how much of a bad shape the Plaguelord economy is in, it's incredibly difficult to get a Dragonliche in play and maintain your position in the game. Many sacrifices have to be made in order to do this and can easily cost the game. However, if you do manage to pull it off, then you have an excellent unit to lead your army into war. With a Dragonliche you can distract archers and tower, allowing for Spores to float on in and implode the enemy base. Similarly, Eyes of Flames can follow safely in the Dragonliche's wake and proceed to burn down towers. With some micromanagement, Plague Priests can work along side Dragonliches to wall almost all enemy attacks - Dragonliches for physical missiles, Plague Priests for elemental attacks.

Lord Antharg - Plaguelords' Titan
One of the strongest melee Titans in the game, Lord Antharg, one of the four horsemen, resembles a mutant green slug, armed with two powerful twin scimitars. Characterized by its fearsome appearance, it has one of the highest damage amounts in the game and is durable and resistant to damage from crushing. Although, his speed isn't the best and his attack type could have been better to take advantage of his immense 36 combat. (But at least it's not piercing like poor King Lunarion's!) Lord Antharg can form a mobile bulwark along side standard Hydras and Plague Priests who, when combined, can sponge nearly anything the enemy can throw at them.