The Root Fossil (Japanese: ねっこのカセキRoot Fossil) is a Fossil introduced in Generation III that can be regenerated into Lileep. It is the counterpart of the Claw Fossil.
From Generation IV onward, the Root Fossil is no longer a Key Item, and is a normal item. Therefore, multiples of them can be obtained, they can be held, and sent to other players via trading.
The Root Fossil was introduced as a Trainer card in the Pokémon Trading Card Game in the EX Sandstorm expansion, first released in the Japanese Miracle of the Desert expansion. Although it is a Trainer card, it is played as if it were a Colorless-type Basic Pokémon. However, Root Fossil can't be affected by any Special Conditions, can't retreat, and the player may choose to discard it at any time during their turn. Additionally, it allows the player to remove one damage counter from Root Fossil between turns. It can evolve into Lileep that evolve from a Root Fossil. During the EX Series, Knocking Out a Root Fossil was not rewarded with a Prize card (it still had to be discarded). This changed in the Diamond & Pearl Series with its reprint in the Legends Awakened expansion, to match the Fossil cards released in the previous expansion.
During the Black & White Series, the Plasma Blast expansion included the Item cardRoot Fossil Lileep. It allows players to look at the bottom seven cards of their deck, reveal a Lileep they find there, and put it onto their Bench. The other six cards are then shuffled back into the deck.
Root Fossils are also featured on Unidentified Fossil cards. These cards are played as if they were Basic Pokémon and can evolve into Lileep.
The Scarlet & Violet Series saw the release of Antique Root Fossil in the Stellar Crown expansion, first released in the Japanese Stellar Miracle expansion. This card is like the previously released Root Fossil card, but with a different Ability that makes it so that if this card is in the Active Spot, the opponent's Active Pokémon's attacks cost more.
Trivia
The symbol for the EX Sandstorm expansion resembles the Claw and Root Fossils.