A third Amiibo was at one stage due to join the upcoming Falco and Fox figures in the Star Fox range.
We were working on a couple of ideas for the game for well over a year,” Nintendo designer Shigeru Miyamoto told Game Informer. There was one point where we had an Arwing Amiibo that would transform into the walker. But it was really tough to execute that in the normal Amiibo size and in a way that met with product-safety standards.
We had to give up on it [but] at some point, if we don't have to do it at Amiibo size, it might be nice to have that Arwing that can transform into a walker.”
The Arwings in upcoming Wii U title Star Fox Zero transform into a two-legged land machine.
As for the other Star Fox Amiibos, Fox unlocks a classic SNES Arwing along with the Corneria music from the original title. It's not yet known what content Falco unlocks.
Star Fox Zero was last night given an April 22nd release date in the UK.