Tummi Gummi is an overweight Gummi, stated to be young as, or younger than, Gusto, who enjoys a good meal, and would rather eat gummiberries than just pick them.
Of all three of the kid Gummis, Tummi is the oldest, making him a teenager. He has a rather relaxed and easygoing personality, which often gets him caught up in Cubbi's schemes. However, in dangerous situations, Tummi has shown exceptional bravery. Throughout the series, he has shown signs of being a talented sailor, gardener, artist and craftsman. Tummi was voiced by Lorenzo Music.
- Tummi and Gusto are the only Gummi Bears to wear sandals.
- He is one of the few Disney characters to commit malapropisms, the other two being Smarty from Who Framed Roger Rabbit and Harry from Stanley.
- Tummi is very similar to Garfield from the cartoon franchise in that they both have gluttonous appetites and are both voiced by Lorenzo Music.
- He is also similar to Broadway from Gargoyles, Rolly from the 101 Dalmatians franchise, Heimlich from A Bug's Life, and Budderball from the Air Buddies series in the very same manner, minus having different voice actors.