Thallid is a special Creature — Fungus card from Time Spiral Timeshifted (TSB), collector number 86. Current market price: $0.46 (foil $2.80), TCGplayer market prices via Scryfall.
At the beginning of your upkeep, put a spore counter on this creature. Remove three spore counters from this creature: Create a 1/1 green Saproling creature token.