Chuckie and Guybrush

Chuckie was the name of Guybrush Threepwood's "creepy brother". He hated and bullied Guybrush, and the reason was that Guybrush broke Chuckie's Junior Ultra Soldier Commando Assault Vehicle™.

LeChuck transformed himself into a human form to convince Guybrush they are brothers, asking Threepwood to remove his zombie mask. After this, they were transformed into children in a theme park.

It is unknown whether Threepwood truly has a brother named Chuckie or LeChuck really and Chuckie were same but assumingly the latter was a lie made by him in order to snare Guybrush.