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 card from your graveyard to the battlefield.
When
Slimefoot and Squee enters the battlefield, it triggers, creating a 1/1 Saproling creature token.
Activate
Viscera Seer by sacrificing
Slimefoot and Squee, and the other creature returned in step 1, if applicable.
When
Slimefoot and Squee and up to one other creature are sacrificed,
Szarel triggers that many times, putting a number of +1/+1 counters equal to
Szarel's power on
Crystalline Crawler for each trigger.
Resolve the
Viscera Seer abilities.
Activate
Crystalline Crawler four times by removing four +1/+1 counters from it, adding ({1} magic symbol) ({B} magic symbol) ({R} magic symbol) ({G} magic symbol) .
Repeat.
Notes
This combo can put infinite +1/+1 counters on each creature you control except
Szarel so long as its power is greater than the mana needed to activate the creature's ability from your graveyard.
Results
Infinite LTB.
Infinite ETB.
Infinite colored mana.
Infinite sacrifice triggers.
Infinite death triggers.
Infinite scry 1.
Infinite +1/+1 counters.
Infinite recursion of creature cards in your graveyard.