Jelly Tyrant

Jelly Tyrants are mind-controlling slime-creatures. They wrap around their victim's head and control their actions, forcing them to walk, fight, or even cast spells.  Typically they hire or abduct a victim of sufficient value, then seek to trade up as stronger hosts become available. Sure, they may trap a sentient creature in a hellish nightmarescape while they drive its body around, but those sentient creatures were probably dicks!

They're surprisingly adventurous critters, even when hostless, but when they're riding around on a human's head, they are fearless. Dangerous in a fight, they rarely stay in one place, leaping from head to head in the fray, staying one enemy's sword, misdirecting an arrow on the next, interrupting spells and generally busting heads.

They're very fond of humans and never have understood the distrust they suffer, although they're also notoriously... unsentimental about their hosts, with little regard for their safety or well-being. You might say they're fond of humans in the same sense humans are fond of particularly ornate wrenches.

A Weird Hero, the Jelly Tyrant can be played in two ways: one, as a mind-controller that coerces a player character to obey his commands, or two, as a cooperative master who directs a mini-party of himself and a willing thrall. For the coerced victim, he may periodically trade out hosts, superimposing skills and bonuses he has onto the template of various NPCs he controls.