Humble the Brute

Instant

Destroy target creature with power 4 or greater.
Investigate. (Create a colorless Clue artifact token with ", Sacrifice this artifact: Draw a card.")

2016-04-08:
The token is named Clue and has the artifact subtype Clue. Clue isn’t a creature type.
2016-04-08:
The tokens are normal artifacts. For example, they can be sacrificed to cast Angelic Purge or targeted by Root Out.
2016-04-08:
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.
2016-04-08:
You can’t cast a spell without choosing legal targets. If all of those targets become illegal, the spell doesn’t resolve and you won’t investigate.