Exotic species aren't so exotic, eh?

[KorvinStarmast]

"Player: Actually, this is a tinkergnome named Thadwitzit whose great life work was building this metal automaton suit of armor for helping his people in mining and exploration. Sadly, because he's a tinkergnome, it only kind of worked and he got trapped inside then buried in a mine collapse. he died a long time ago, but years later, when the other gnomes dug up the armor, it was somehow automated as if by the spirit of Thadwitzit. Now he wanders the earth in his metal form, the decayed skeleton of his former self still strapped into the cockpit in the chest, trying to figure out who he really is. "

"DM: Oh, okay then."

If the two work together to find a way to make it work and fit into the game world, then Good Job To Them Both!
(IME players who go to the effort to make it fit are usually worth working with on any number of things, not just chargen).