- “What in Great Gummi do you think you’re doing?”
- ―Gruffi Gummi
Gruffi is an old-fashioned bear who prefers to do things "the Gummi way" and the de facto leader of Gummi Glen. He can be overly strict, serious, and irritable, but he is respected for his common sense and is considered a voice of stability. He is a skilled craftsman, and is usually the one to repair Gummi technology and build traps to deal with ogres and humans. As a craftsman, he tends to be a perfectionist, which can be his undoing at times. He was initially distrustful of Cavin, the first human he made contact with, but Gruffi would later admit that he secretly liked the boy.
- Conservative to the very soles of his feet, Gruffi Gummi is never truly happy unless he has something to be unhappy about.
At the beginning of the show, Gruffi is part of a small caretaker colony who live at the ancestral home of the Gummi Bears, Gummi Glen. Though the colony once was fairly large, it has since dwindled, along with the Gummi's knowledge of their past. After an encounter with a boy named Cavin, Gruffi's fellow gummi, Zummi gains a Gummi Medallion. The medallion not only allows Zummi to open "The Great Book of Gummi," which contains all the knowledge of the Gummi Bears, but allows Zummi to perform magic. Gaining the knowledge they had lost, Gruffi takes up the role of protecting the nearby kingdom of Dunwyn while repairing the long dormant Gummi technology.
Early on, Gruffi was shown to clash with Grammi. The two were forced to work together when all the other Gummis were turned to statues; Grammu and Gruffi would have to repair a broken tablet that contained the counterspell. Later on, Gruffi would get in trouble with his headstrong tactics, becoming the victim of a Slumber Sprite which put him to sleep. Grammi would have to take Cubbi on a journey to find the sprite, and found herself having to convince Cubbi to take a more cautious approach as opposed to Gruffi's more forward methods.
Gruffi would be one of two Gummis to discover Gusto, a lone Gummi who had been on a deserted island for years. Gruffi would help rescue Gusto but often found himself clashing with Gusto, due to the younger Gummi's outside the box thinking. At one point, Gruffi would accidentally destroy the Great Book of Gummi, forcing him to travel to the abandoned city of Ursalia to replace it. He would meet Sir Thornberry, an older and somewhat eccentric Gummi Knight. Gruffi would only find a bookmark and return home saddened, but was shocked to see the bookmark magically restore their Great Book.