Treat Saporlings as a Fungus.

At your end step, put a Spore counter on each Fungus.

{G}, or sacrifice a Fungus with 2 or more Spore counters: Create a 1/1 green fungus creature token called "Thallid" that reads, "During your upkeep, put a spore counter on Thallid. {0}: Remove three spore counters from Thallid to put a Saproling token into play. Treat this token as a 1/1 green creature."