There are many types, actually. And they arent even cogs!
Cave Spider (Minecraft)
Chronos (Greek Mythology)
Death's Apprentice (fanmade minecraft)
Death (fanmade miecraft)
An eight legged creature from minecraft. Common in EBHQ and locations that have spider webs.
Same as spider except venom has a more damage per round effect
Venom (-5, -10 every other round)
The infamous creeper may scare even the most brave of toons.
Creep (10 & -20 every other round)
Kronos is the leader titan in Greek Mythology
Summon (summons 3 titans to help Kronos)
(Will make your laff meter look sad and take damage over time)
(Summons a Wither Skeleton to help him in battle)
Please see: http://minecraftfanfictions.wikia.com/wiki/Death