You control at least one additional nontoken creature that does not have flying.
Steps
Activate
Phyrexian Altar twice by sacrificing
Slimefoot and Squee and another nontoken creature without flying, adding ({B} magic symbol) ({R} magic symbol) .
When
Slimefoot and Squee and the other creature die,
Luminous Broodmoth triggers twice.
Resolve the first trigger, returning
Slimefoot and Squee from your graveyard to the battlefield with a flying counter on it.
When
Slimefoot and Squee enters the battlefield, it triggers, creating a 1/1 Saproling creature token.
Resolve the second
Luminous Broodmoth trigger, returning the other creature from your graveyard to the battlefield with a flying counter on it.
Activate
Phyrexian Altar twice by sacrificing
Slimefoot and Squee and the other creature, 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 the other creature from your graveyard to the battlefield.
Repeat.
Results
Infinite creature LTB.
Infinite creature ETB.
Infinite creature sacrifice triggers.
Infinite death triggers.
Infinite colored mana.
Metadata
In 4 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).