Slender Zombies do more damage, have longer legs and arms, and are slightly faster than Normal Zombies. Their eyes glow, and are especially visible at night.
Slender Zombies are found in the Tall Grass Lands, and they also spawn on top of the player whenever the Cursed AK (a powerful variant of the AK-74) is picked up.
Slender Zombies are fast, and quickly gain on players who are going any speed slower than running. If Slender Zombies gain on you, try using melee weapons to kill them. When a Slender Zombie attacks a player, the player will, more often than not, get a glitchy and shaky screen, making aiming significantly harder.
If you are far away, then longer ranged weapons can take them out, however, Slender Zombies take considerably more bullets than normal zombies. Weapons with good knockback like the Knockback Gun or the Model SB can prove quite effective against single Slender Zombies.
The slender zombies seem to be a zombie version of the ☀キキング・ジン troops in TABS.