Soul's Attendant + Herd Baloth + Spider-Man, Peter Parker
Soul's Attendant
Herd Baloth
Spider-Man, Peter Parker
Infinite creature ETBInfinite lifegain triggersInfinite lifegainInfinite creature tokensInfinite +1/+1 counters on a creature
How it works
Gain life.
Spider-Man triggers, putting a +1/+1 counter on Herd Baloth.
Herd Baloth triggers, creating a creature token.
When the creature token enters the battlefield, Soul's Attendant triggers, causing you to gain 1 life.
Repeat from step 2.
This loop relies on a closed-loop trigger chain that feeds itself indefinitely once you initiate it by gaining life. That initial life gain makes Spider-Man, Peter Parker trigger to place a +1/+1 counter on Herd Baloth, which in turn prompts Herd Baloth to spawn a 4/4 green Beast token. The arrival of that token is all Soul's Attendant needs to grant you another life gain trigger, looping right back into Spider-Man, Peter Parker's ability to keep the cycle spinning.