Trolls

Trolls are the main alien species from Homestuck. In Sugoi Quest for Kokoro, they live alongside humans and can even breed with them (unlike in Homestuck, where such a thing is impossible, because Trolls use giant moth creatures to make their offspring for them). Trolls are capable of gaining Neko, Angel, and Demon powers.

For more on the cultural differences and advanced biology that Trolls possess, I recommend reading the Troll article over on MS Paint Adventures wiki. That is, if you have time and don't know what the fuck Homestuck is.

Appearance
Trolls always have black hair, orange horns in different shapes and sizes (they also look like candy corn), and grey skin. They have 12 different blood castes consisting of rust red, brown, mustard yellow, candy red (this is a rare mutation that usually gets a Troll killed), olive green, jade green, teal, cerulean, blue, purple, tyrian purple, and the rare and royal fuschia. Only trolls with tyrian purple and fischia blood have ear fins and gills. Trolls also have personal symbols on their clothes, and their clothes are always black and grey, or mostly black and grey. When they're first born they start out as weird bug things with normal people heads, it's gross. But in Sugoi Quest for Kokoro, you usually say "fuck that" to most of the shit on this list (except the bug baby shit, usually).

Wanna give the Trolls weird colorful hair? Fuck yeah. Wanna make their symbols something fucking stupid? go for it. Wanna give them glitter pink blood? Nobody's stopping you. Thinking of giving them overpowered abilities? Sue-ish or edgy names and themes? Star horns? Normal human customs and breeding? Animal tails and ears? Fucking do it my man. The sue-ish Trolls are embraced here. Go on ahead and live your fucking life.

Or if you want you can just make a normal Troll with some sue-ish shit, if that's your deal. Whatever you want, friends.