When Infested Thrinax enters the battlefield, it triggers, causing you to create a number of 1/1 Saproling creature tokens when a nontoken creature you control dies.
Activate Phyrexian Altar by sacrificing Slimefoot and Squee, adding ({B} magic symbol) .
When Slimefoot and Squee dies, Infested Thrinax triggers, creating three 1/1 Saproling creature tokens.
When Infested Thrinax dies, its delayed ability triggers, creating four 1/1 Saproling creature tokens.
Activate Phyrexian Altar twice by sacrificing two Saproling tokens, adding ({1} magic symbol) ({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 Infested Thrinax from your graveyard to the battlefield.
When Slimefoot and Squee and Infested Thrinax enter the battlefield, they each trigger.
Resolve the Slimefoot and Squee trigger, creating a 1/1 Saproling creature token.
Resolve the Infested Thrinax trigger, causing you to create a number of 1/1 Saproling creature tokens when a nontoken creature you control dies.
Activate Phyrexian Altar by sacrificing Slimefoot and Squee, adding ({B} magic symbol) .
When Slimefoot and Squee dies, Infested Thrinax triggers twice, creating six 1/1 Saproling creature tokens.
You may repeat steps 12 and 13 once for another nontoken creature you control, if desired.
Activate Phyrexian Altar three times by sacrificing three Saproling tokens, adding ({1} magic symbol) ({R} magic symbol) ({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 up to one other creature from your graveyard to the battlefield.
When Slimefoot and Squee enters the battlefield, it triggers, creating a 1/1 Saproling creature token.