So I saw a thread regarding the pokemon on the left and trying to find out what it is. I think a good way of approaching this is to find out what it's supposed to represent.
Given what we know about tengu I'm guessing this is a far more bird like tengu in general with more avian features then some of you here are used to. Firstly within it's left hand you can clearly see a sword of some kind, which tengu are known to hold from time to time. But what is most important is that thing in it's left hand. Now it really does just look like a shovel but given it's shape and that it appears to be attack with it I think this might be a hauchiwa. A hauchiwa is this sort of magical fan thing that tengu are iconic for holding. So I'm pretty confident this is a traditional avian tengu, so what pokemon does that leave us with?

Well there's a lot of bird pokemon out there, but I feel as if an evolution to a hisuin golduck. What do I have to support this? Basically nothing besides that it would make sense to give this gen 1 pokemon some love again and the fact that psyduck is featured in the games promotional material. Thank you for coming to my Ted Talk