Stalking Devourer

Enrage - Whenever Stalking Devourer is dealt damage, you may Exert up to one creature you
don't control. (An Exerted permanent won't
untap during it's controller's next untap step.)
Devour(When this creature enters the battlefield, you may sacrifice any number of other creatures. For every creature sacrificed this way, put a +1/+1 counter on this creature.)
"It followed us from a distance all the way clear to the other outpost, eyeing us the hole way there."