Play Root Fossil as if it were a Basic Pokémon. While in play, Root Fossil counts as a   Colorless Pokémon  (as well as a Trainer card). Root Fossil has no attacks of its own, can’t retreat, and can’t be  affected by any Special Conditions. If Root Fossil is Knocked Out, it doesn’t count as a Knocked  Out Pokémon. (Discard it anyway.) At any time during your turn before your attack, you may discard  Root Fossil from play.

Spongy Stone:

At any time between turns, remove 1 damage counter from Root Fossil.