Play Claw Fossil as if it were a Basic Pokémon. (Claw Fossil counts as a Trainer card as well, but if Claw Fossil is Knocked Out, this counts as a Knocked Out Pokémon.) Claw Fossil can't be affected by any Special Conditions and can't retreat. At any time during your turn before your attack, you may discard Claw Fossil from play. (This doesn't count as a Knocked Out Pokémon.)
If Claw Fossil is your Active Pokémon and is damaged by an opponent's attack (even if Claw Fossil is Knocked Out), put 1 damage counter on the Attacking Pokémon.