Slimefoot and Squee | Phyrexian Altar | Priest of Urabrask

Cards

({1} magic symbol) , plus either ({B} magic symbol) , ({R} magic symbol) or ({G} magic symbol) available available.

Activate
Phyrexian Altar twice by sacrificing
Priest of Urabrask and
Slimefoot and Squee, adding two mana in any combination of ({B} magic symbol) , ({R} magic symbol) or ({G} magic symbol) .
Activate
Slimefoot and Squee by paying ({1} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) and sacrificing a Saproling, returning it and
Priest of Urabrask from your graveyard to the battlefield.
When
Priest of Urabrask and
Slimefoot and Squee enter the battlefield, their abilities trigger.
Resolve the
Priest of Urabrask trigger, adding ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Resolve the
Slimefoot and Squee trigger, creating a 1/1 Saproling creature token.
Repeat.