Krenko, Tin Street Kingpin is a rare Legendary Creature — Goblin card from March of the Machine Commander (MOC), collector number 287. Current market price: $3.80, TCGplayer market prices via Scryfall.
Whenever Krenko attacks, put a +1/+1 counter on it, then create a number of 1/1 red Goblin creature tokens equal to Krenko's power.