Dimir House Guard is a common Creature — Skeleton card from The List (PLST), collector number RAV-83. Current market price: $0.16, TCGplayer market prices via Scryfall.
Fear (This creature can't be blocked except by artifact creatures and/or black creatures.) Sacrifice a creature: Regenerate this creature. Transmute {1}{B}{B} ({1}{B}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)