Zombie Units

Defensive and Offensive Units (Available to attack and to defend)

Walkers are the basic Zombie unit. They are cheap to build and consume the minimum unit points. Use them in small groups of 5-6 to attack from different directions while trying to avoid bomb traps and bazooka strikes.
Stats
Health: 250 hit points
Attack Damage: 40 per attack (Melee)
Multiple targets?: No (single target)
Detection range: Low
Coins cost: 100
Supplies cost: 0
Unit points cost: 1

Resilient Zombies take the role of tanks. They can absorb a good amount of damage. Send the Resilients at the front of the pack to absorb damage while the other Zombies, like Walkers for example, advance behind them.
Stats
Health: 800 hit points
Attack Damage: 60 per attack (Melee)
Multiple targets?: No (single target)
Detection range: Normal
Coins cost: 250
Supplies cost: 100
Unit points cost: 3

If you want to rush the attack, nothing better than sending a group of Enraged Zombies. They deal a lot of damage and they are the fastest of all units. But, on the other hand, Enraged ones can't take a lot of damage so they need some protection. Pro tip: Send a nice group of Resilient Zombies to the front and calculate the time to send a pack of enraged Zombies to follow them behind.
Stats
Health: 500 hit points
Attack Damage: 200 per attack (Melee)
Multiple targets?: No (single target)
Detection range: High
Coins cost: 500
Supplies cost: 500
Unit points cost: 4

Zombies evolved and we got Mutants now. They are smarter and very strong, dealing a lot of damage on par with their high damage output. A small group of 4-5 mutants can easily wipe groups of Human units without a sweat. Also, and as a bonus, Mutants swing their arms when attacking and they can hit multiple targets with every attack (max 3 targets).
Stats
Health: 4,000 hit points
Attack Damage: 300 per attack (Melee)
Multiple targets?: Yes (max 3 targets)
Detection range: High
Coins cost: 2,500
Supplies cost: 2,000
Unit points cost: 6

Defensive Units (Only available to defend your town as "traps")

Ambushers remain hidden until an enemy walks nearby (within its detection radius). Once an enemy is detected, the Ambusher makes his entrance after 2 seconds, being immune to any damage during the first 10 seconds of his attack.
Try placing Ambushers in corridors or at corners of streets to increase their potential.
Stats
Health: 1,000 hit points
Attack Damage: 250 per attack (Melee)
Multiple targets?: No (single target)
Detection range: High
Coins cost: 8,000
Supplies cost: 5,000

Abilities (Only available when attacking)

Fear

Use the Fear ability to immobilize your enemies in an area of effect. Enemies that are feared, will be unable to attack your units for 10 seconds and that's enough time to plan a nice strategy around that.
The area of effects lasts 15 seconds and affects every units that already is in the area or any unit that enters the area during that time.
Stats
Health: This ability has no health
Attack Damage: No damage (Crowd control for 10 seconds)
Multiple targets?: Yes, area of effect
Detection range: Normal (area)
Cost: 1 Fear Token
Cooldown: 20 seconds

Poison Cloud

Deal considerable damage by casting a Poison Cloud to groups of units, so they can receive damage over time during 10 seconds. Specially useful against weaker units like Scouts and Snipers, but also to weaken heavier units like Gunners or Bazooka soldiers.
The area of effects lasts 10 seconds and affects every units that already is in the area or any unit that enters the area during that time.
Stats
Health: This ability has no health
Attack Damage: 100 poison damage per tick (2 ticks total)
Multiple targets?: Yes, area of effect
Detection range: Normal (area)
Cost: 1 Poison Cloud Token
Cooldown: 30 seconds

Abomination

Raise an Abomination from the ground when it's time to bring chaos. They deal a lot of damage and can also take an equal amount. Raise them behind enemy lines to open up a way for the rest of your units to advance.
Stats
Health: 3,000 hit points
Attack Damage: 300 per attack (Melee)
Multiple targets?: Yes (max 3 targets)
Detection range: High
Cost: 1 Abomination Token
Cooldown: 45 seconds