Bygone Bishop

Flying
Whenever you cast a creature spell with mana value 3 or less, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Shadows over Innistrad Remastered

Commander Legends: Battle for Baldur's Gate

Crimson Vow Commander

Flying
Whenever you cast a creature spell with mana value 3 or less, investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")

Shadows over Innistrad Promos

Shadows over Innistrad

Flying
Whenever you cast a creature spell with converted mana cost 3 or less, investigate. (Put a colorless Clue artifact token onto the battlefield with "{2}, Sacrifice this artifact: Draw a card.")

Casting a spell for an alternative cost, such as a madness cost, doesn't change its mana value. For example, casting Twins of Maurer Estate (a card with mana cost {4}{B} and madness cost {2}{B}) for its madness cost will not cause Bygone Bishop's ability to trigger.

If you sacrifice a Clue for another card's cost or effect, such as that of Angelic Purge or Tamiyo's Journal, you can't also pay {2} and sacrifice it to draw a card.

The token is named Clue Token and has the artifact subtype Clue. Clue isn't a creature type.

The tokens are normal artifacts. For example, they can be sacrificed to cast Angelic Purge or targeted by Root Out.