guyfuy did this awesome picture for me in his stream today.
Original is here http://www.furaffinity.net/view/5634895 PLEASE comment and fave him first. Just made a couple vanity edits of my own and colored it xP

Just big ol fat butt Alter if he was a homestuck troll, or dressing up like one, idk xP
I consider it Alter just dressing up, but others call it a fan-troll. So call it whatever you want.

A bit more story:
If we wanna consider this Alter in Homestuck, then he's a troll, named Atargi Dugora, that didn't leave the planet like he should have, so he bugs all the younger trolls and takes their food from them.
His blood is dark red like Aradia but he wears purple shades to hide his eyes and his symbol is purple to make other trolls think he's of higher blood.
His Trollian handle is artisticallyDesperate.
His horns are curved and pointed, though one is longer than the other.
His typing quirk is making all o's into O's and capitalizing any word having to do with weight or food or eating as well as adding ♥'s to the start and end of every sentence.
He wormed his own way into Sgrub by using a laptop and computer to be his own sever player.
His planet is the Land of Pizzas and Pop.
His strifekind is Sporkdentkind, basically it's like Feferi's, but on one end is a spoon and the other is a fork.