Young Wolf dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
Activate
Thermopod by sacrificing
Young Wolf.
When
Young Wolf dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Young Wolf enters and dies as a state-based action due to having 0 toughness. Its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
Repeat from step 3.
Notes
If
Young Wolf starts with a +1/+1 counter on it, then you may start the combo from step 3 instead.
Results
Infinite creature ETB.
Infinite creature LTB.
Infinite death triggers.
Infinite red mana.
Infinite creature sacrifice triggers.
Metadata
In 0 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Spicy (Bracket 3-4+).