Smudge (originally Cascão – Portuguese for a dirt layer that may appear on the human skin when not washed frequently - in the Brazilian version) is one of the main characters of Monica's Gang.

[2] Mauricio de Sousa, his creator, says he based the character on a child he knew while growing up in Mogi das Cruzes.

He also happens to be Jimmy Five's best friend, he is always convinced or even blackmailed to participate in his "infallible plans", even though in the end he is always the one to mess everything up because he always lets the cat out of the bag.

He dates Dustine (Cascuda) - a girl who hates water just like him but takes a bath every few stories, unlike Smudge.

In 2002 the football player Ronaldo made a haircut inspired by Smudge playing well during the 2002 FIFA World Cup.

This was acknowledged in an advertisement for Guaraná Antarctica aired shortly after the World Cup, in which Smudge and Ronaldo interact with each other.