Hovel Hurler dies, its undying ability triggers, returning it from your graveyard to the battlefield without a +1/+1 counter on it due to its replacement effect.
Repeat.
Notes
Once you have enough colored mana, you can remove the additional -1/-1 counter each loop from
Hovel Hurler to give your other creatures infinite power.
Results
Infinite ETB.
Infinite LTB.
Infinite death triggers.
Infinite red mana.
Infinite sacrifice triggers.
Infinitely powerful creatures you control until end of turn.