Crusty Sean did not originate from fanon, and the information on this page may not be entirely accurate to their canon. You may read more about this subject in the context of their canon on the following wiki(s):
“This is Crusty Sean, the owner and proprieter of Shrimp Kicks. He’s got a mean shoe game and plenty of feet that he uses to model all of the hottest new styles. He might look like he’s fried to golden-brown perfection, but his breaded exterior is actually a slightly morbid designer jacket.”
— Splatoon Official tumblr
Crusty Sean's basic appearance
Japanese Tiger prawn
Crusty Sean is a shrimp-like character that owns the Shrimp Kicks store in Inkopolis, which sells shoes the Inklings can wear.
Sean is a bit obsessed with wearing as much of his favorite shoes at the same time, having eight legs with mismatched shoes to show that. Sean is also known to be carelessly friendly at times.
Crusty Sean resembles a red-orange Japanese tiger prawn, with eight legs and two claws. He also wears a purple knitted hat with a yellow label. The most notable thing of Sean's appearance is the slightly morbid designer jacket he's wearing, which is woolly and bread-like. With this jacket on, Crusty Sean slightly resembles a fried tempura shrimp, with the jacket being its crust.