Sebastian first appeared when he wanted to use the bathroom, but keeps getting denied as Leni goes past him so she can go in there to talk to her work friends.
He made a cameo in "Camped!" and later in "Bummer Camp" playing with other kids in Camp Mastodon.
Appearance[]
He is a small and thin Asian boy with tan skin. He has a hairstyle almost identical to Lincoln's, but it's black. He wears a yellow T-shirt, blue jeans, and white sneakers with black stripes.
The Loud House Encyclopedia