I've just been listening to the archives of the fear the boot podcast and it's discussed in episode 13 you can find on this page. The name they gave it is the freak show syndrome. The problem is not that the players who do that are choosing weird races and features for their PCs. It's more about implicit powergaming, or not wanting to write down a real character and a decent background story, or sometimes just a symbolic way to express they don't care.
Do you feel like those player are testing your authority as GM ? To me they're plain weird to come to you with such lame PC concepts... Unless it's just that they played too many MMORPGs
Au gibet noir, manchot aimable, dansent, dansent les paladins
Les maigres paladins du diable les squelettes de Saladins.