Throt The Unclean

When Throt enters the battlefield, create two skavenslave tokens. (They're 1/1 black and red Rat creatures with "This creature can't block")
Tap three untapped Rats you control: Create a Warpstone token. (It's an artifact with "{t}, discard
a card, sacrifice this token: Add two many of any one
color")
Whenever you sacrifice a Warpstone, put two
+1/+1 counters on target Rat you control.