An artistic, individualist Gummi who was stranded on a deserted island for twelve years with his best friend Artie Deco, a wise talking toucan. Tummi and Gruffi were shipwrecked on Gusto's island, just as a volcano was due to erupt and cause the island to sink into the sea. The three bears worked together and brought Gusto home with them to Gummi Glen during season 2. Gusto's personality is mercurial, in sharp contrast to Gruffi's desire to be steady and "do things the Gummi way". Gruffi tends to argue with Gusto for his outside-the-box thinking, and how much influence he is on Cubbi and Sunni, although there are times when Gusto's uniqueness saves the day, such as figuring out how to escape the island. He lives by himself in a makeshift apartment behind a waterfall, but lives in Gummi Glen when the weather is too harsh.
- Gusto and Tummi are the only Gummi Bears to wear sandals.
- Gusto is similar to Banjo the Bear from the Banjo-Kazooie game series in the sense that they are both bears with birds for best friends.