Chime
Skeletron Prime
Possibly. I mean if it's not bothering anything I'm not concerned about it. LolWell, there are multiple parallaxes for each biome that is generated upon world creation. It could be that just this one is borked, and not the rest of them, and that the Menu Screen randomly chooses one parallax which is why you only see the glitch every so often. Your world might not have -this- parallax.