Lonis, Cryptozoologist

Whenever another nontoken creature you control enters, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

Murders at Karlov Manor Commander

Whenever another nontoken creature enters the battlefield under your control, investigate.
{T}, Sacrifice X Clues: Target opponent reveals the top X cards of their library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield under your control. That player puts the rest on the bottom of their library in a random order.

The List

Jumpstart: Historic Horizons

Modern Horizons 2

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, one can be sacrificed to activate the ability of Breya's Apprentice and one can be the target of Break Ties.

You can't sacrifice a Clue to activate its own ability and also to activate the ability of Lonis, Cryptozoologist.