Phyrexian Gremlins is a common Creature — Phyrexian Gremlin card from Antiquities (ATQ), collector number 18. Current market price: $1.06, TCGplayer market prices via Scryfall.
You may choose not to untap this creature during your untap step. {T}: Tap target artifact. It doesn't untap during its controller's untap step for as long as this creature remains tapped.