Eloise, Nephalia Sleuth

Whenever another creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

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Whenever another creature you control dies, investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Whenever another creature you control dies, investigate.
Whenever you sacrifice a token, surveil 1.

Eloise's last ability triggers whenever you sacrifice any token for any reason, not just whenever you sacrifice Clue tokens.

If you create a token that's a copy of Eloise and both are legendary, you will choose either the token or the original Eloise to keep and put the other into the graveyard. This is not the same as sacrificing it. Putting the token into the graveyard won't cause nontoken Eloise's last ability to trigger.

If you sacrifice a Clue token, Eloise's last ability will trigger in response. You'll surveil before drawing the card.