Breath of Fury + Ogre Chitterlord + The Fire Crystal
Breath of Fury
Ogre Chitterlord
The Fire Crystal
Infinite creature ETBInfinite combat phasesInfinite creature tokens with hasteInfinite creature LTBInfinite combat damageInfinite death triggersInfinite mana creatures you control can produceInfinite creature sacrifice triggersInfinite untap of creatures you controlInfinitely powerful Rats you control until end of turn
How it works
Declare the creature with Breath of Fury attached and Ogre Chitterlord as attackers.
Ogre Chitterlord triggers, creating two creature tokens.
Deal combat damage using the creature that has Breath of Fury attached.
Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to a creature token, then causing you to untap all creatures you control and to get an additional combat phase after this one.