Heroes' Bane's ability by paying ({2} magic symbol) ({G} magic symbol) ({G} magic symbol) , putting at least five +1/+1 counters on it.
Activate
Necrotic Ooze using
Crystalline Crawler's first ability four times by removing four +1/+1 counters from it, adding ({2} magic symbol) ({G} magic symbol) ({G} magic symbol) .
Repeat.
Results
Infinite +1/+1 counters on a creature.
Infinite colored mana.
Metadata
In 7 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).