With the vast amount of X-men characters over the years, there are bound to be a few which, looking back on, just seem far too creepy to ever appear in a comic nowadays. Or when reading just send a shiver up your spine with how disturbing they are.
My two:
Pretty Boy the Reaver. The whole point of this character seem to be implied rape, both of the mind and the body, always targetting female X-men and the way the filaments came out of his eyes was very creepy.
Spat from the trial of Gambit
God knows what Scott Lobdell and Joe Madureira were thinking of when creating this character. She has the mind of a fully grown woman and the body of a child. Plus walks around in a furry bikini and has a giant slug as a partner - very wrong in my opinion. (As an aside, why is "attractive female" listed as a power on comicvine? lol http://www.comicvine.com/spat/4005-24063/ )
Any others you can think of?