Colfenor, the Last Yew | Gutter Grime | Blasting Station (and one other card)

Creature castable for

Cards

Gutter Grime has slime counters on it at least equal to the toughness of the creature card in your hand.

Cast the creature card in your hand by paying ({0} magic symbol) .
Either that creature dies as a state-based action due to having zero toughness, or activate
Blasting Station by sacrificing that creature.
Gutter Grime and
Blasting Station trigger.
Resolve the
Gutter Grime trigger, putting a slime counter on it and creating a X/X Ooze creature token.
Resolve the
Blasting Station trigger, untapping it.
Activate
Blasting Station by sacrificing the Ooze.
When the Ooze dies,
Colfenor and
Blasting Station trigger.
Resolve the
Colfenor trigger, returning the creature card from your graveyard to your hand.
Resolve the
Blasting Station trigger, untapping it.
Resolve the
Blasting Station activated abilities, dealing 1 damage each time.
Repeat.

This combo also puts infinite slime counters on
Gutter Grime, allowing you to easily create additional infinitely large creature tokens.

This combo has been estimated to be Exhibition (Bracket 1+).