Ninja

The Ninjas are fast units easily getting rid of Light units. In both version, Samurai are always a nightmare for them

Computer
Ninja's dagger is no match for Lights units such as Newbies, Novices or even Monks. Their attack has 0.5 superior range to most unit, meaning they can deliver a hit or two before the enemy engage combat. The Samurai are an early counter to Ninja swarms and later on, Mages will do the trick even better as Ninja won't be able to engage combat
 * Cost: 45
 * Supply: 1
 * Income: 8
 * HP: 100
 * Armor Type: Light (0)
 * Move Speed: 3.2
 * Damage vs Light: 22
 * Damage vs Armored: 10
 * Attack range: Melee (1.5)
 * Weapon Speed: 1.3

Mobile
Still effective at taking out Light units, Ninja can be useful against some new units such as Battle Cats. In reality, most players tend to replace them with Skeletons for additional stat and a special skill. Some even prefer Beasts as a replacement. This is due to Ninja's stats not being so incredible and the arrival of counters which can clear them even faster than Samurai (Boar Fighters and Centaurs notably)
 * Cost: 49
 * Supply: 1
 * Income: 8
 * Unit Type: Light anti light
 * Move Speed: 3.25
 * HP: 98
 * Armor Type: Light (0)
 * Damage vs Light: 22
 * Damage vs Armored: 9
 * Attack Range: Melee (1.1)
 * Attack Speed: 1.6
 * Special Skill: none