So-fish-ticated

Bea and Milo try to help Oscar pick out a tie, but when Milo is barred from the store because of his ice cream-stained shirt, he enlists his friends to teach him how to become sophisticated.

Credits
Mouse is singing. Snake asks Mouse if she can teach her to sing. Mouse tells Snake to just open her mouth. Snake does, and a mouse yells "Hey, shut the door. I'm trying to get digested in here!" The mouse goes back in Snake's mouth, and Mouse says "Father?".