Talk:Undyne/@comment-24524076-20160616214208/@comment-28546429-20160731212456

Mettaton EX was being built at that time, when you battle Metta, he says how he's been wanting to flip his switch for so long, but it was being built. In fact, it  was still  being built at that time.

To answer your question, I'll make it as simple as possible:

It's mettaton. The guy who bites his lip when you hurt him.

Literally, the Mettaton page is pretty much all "I promised myself I wouldn't be attracted to a robot..."