Spikeshell Harrier is a uncommon Artifact Creature — Robot Turtle card from Aetherdrift (DFT), collector number 65. Current market price: $0.16 (foil $0.29), TCGplayer market prices via Scryfall.
When this creature enters, return target creature or Vehicle an opponent controls to its owner's hand. If that opponent's speed is greater than each other player's speed, reduce that opponent's speed by 1. This effect can't reduce their speed below 1.