Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Krenko, Tin Street Kingpin

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.

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Trample, haste
Alliance — Whenever another creature you control enters, double this creature's power until end of turn.