({1} magic symbol) , plus either ({B} magic symbol) , ({R} magic symbol) or ({G} magic symbol) available available.
Steps
Activate Phyrexian Altar twice by sacrificing Chancellor of the Forge 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 Chancellor of the Forge from your graveyard to the battlefield.
When Chancellor of the Forge and Slimefoot and Squee enter the battlefield, their abilities trigger.
Resolve the Slimefoot and Squee trigger, creating a 1/1 Saproling creature token.
Resolve the Chancellor of the Forge trigger, creating at least three 1/1 Phyrexian Goblin creature tokens with haste.
Activate Phyrexian Altar four times by sacrificing two Phyrexian Goblins, Chancellor of the Forge and Slimefoot and Squee, adding ({1} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) .