Ugliest 1PP playable species, based on official artwork, any system

[Metastachydium]

I really hated the design of 3.5e Goliaths, with their "gonk-y" faces, gangly limbs, patchy skin and weird nodules (albeit ones with a cool name, lithoderms) making them all look vaguely... diseased in some way.

In that case, I'm sure you love their graceful, hairy cousins, the likewise playable feral garguns (from the same book)!

I'm gonna pass on rating ugly art, tho, because it's just going to come down to which 3e-era artists I didn't like the styles of, like Thomas Baxa and Ron Spencer, and that's just a difference of tastes, the artists don't deserve the slam, and the races don't deserve the dragging.

I mean, some playable critters absolutely deserve the dragging and calling them ugly is, if anything, a praise to the artist. (I'm looking at you, athach, you and your 14 RHD with +5 LA that are totally worth tanking.)