As derived from the wiki:

"Goob is one happy craft! He loves to spend time with family! His sister Scraps is never far! Goob teaches children that hugs are some of the best medicine to a frown!"

Goob is a kind and sociable Toon known for his energetic and innocent personality. Goob is also easily excitable, further adding to his cheerful and approachable nature. As shown in his dialogue, he looks up to his older sister, Scraps.

I don't have a voice in mind. Give me your best shot, and i'll pick what feels best! :] A younger boy, a silly deeper voice, anything you'd like!