Your search for "Undercellar Myconid 150" revealed the following:
Undercellar Myconid (CLB) from Commander Legends: Battle for Baldur's Gate, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: David Szabo Card Text:Whenever Undercellar Myconid enters the battlefield or dies, create a 1/1 green Saproling creature token.T: Add one...
Undercellar Myconid (J25) from Foundations Jumpstart, available at 401 Games Canada. Rarity: Common Finish: Normal Artist: David Szabo Card Text:Whenever Undercellar Myconid enters or dies, create a 1/1 green Saproling creature token.T: Add one mana of any color.