Steelfin Whale

Creature — Whale

Produces: a creature untapping.

Cares about: an artifact entering the battlefield.

Partners

504 cards can cause a creature untapping.

1. Fishing Pole — When Steelfin Whale untaps, Fishing Pole triggers

1,090 cards can cause an artifact entering the battlefield.

1. Leonardo da Vinci — When a Thopter enters thanks to Leonardo da Vinci, Steelfin Whale untaps itself
2. Urza's Command — When a Powerstone enters thanks to Urza's Command, Steelfin Whale untaps itself
3. Spawning Pit — When a Spawn enters thanks to Spawning Pit, Steelfin Whale untaps itself
4. Basalt Golem — When a Wall enters thanks to Basalt Golem, Steelfin Whale untaps itself
5. Sai, Master Thopterist — When a Thopter enters thanks to Sai, Master Thopterist, Steelfin Whale untaps itself
6. Threefold Thunderhulk — When a Gnome enters thanks to Threefold Thunderhulk, Steelfin Whale untaps itself
7. Castle Doom — When a Robot enters thanks to Castle Doom, Steelfin Whale untaps itself
8. Simulacrum Synthesizer — When a Construct enters thanks to Simulacrum Synthesizer, Steelfin Whale untaps itself

239 other cards cause it too, equally specific. The ones shown are the best connected.