Echtheos, from the Depths

Hexproof
At the beginning of your upkeep, create a 1/1
Black Tentacle Creature token with "{u}{b}, {t}: Sacrifice this creature, gain control of target creature for as long as you control Echtheos."
Whenever you gain control of a creature you
don't own draw a card. Whenever you lose
control of a creature you don't own discard two
cards.