Cybermat is a uncommon Artifact Creature — Robot card from Doctor Who (WHO), collector number 175. Current market price: $0.32 (foil $0.55), TCGplayer market prices via Scryfall.
Skulk (This creature can't be blocked by creatures with greater power.) Whenever this creature attacks and isn't blocked, it gets +X/+0 until end of turn, where X is the number of attacking artifact creatures.