Rift Scuttler, River Guardian

Eminence — Whenever another crab you control becomes tapped, if Riff Scuttler is in the command zone or on the battlefield, create a 1/1 token that's a copy of that creature.

If Riff Scuttler is in your command zone, play with the top card of your library revealed and you may play the top card of your library.

Crabs you control have {u}: Untap this creature.