Uto is a dim-witted brown-furred male who likes poking Kago and throwing things off cliffs to find out if they can fly and doesn't like being called "Banana Brain". Uto is slightly larger than Kago and rather fatter than him.
However, Kago is a thuggish blackback, much more intimidating than Uto, and more intelligent. Unfortunately he gets the hiccups when he gets angry, and he gets angry when he gets the hiccups, and he dislikes being poked by his brother and being insulted. He enjoys smashing things.
While both lack self-control, they are extremely strong with a great deal of stamina. It is not entirely clear which brother is stronger, as Kago can smash rocks for hours without tiring or even getting bored, and Uto can pin the exceptionally strong Kago and shakes off his punches easily. If Mama Gunda had sent them both up against Kerchak as she had originally planned, it is very likely that the two of them could have overpowered him.
Uto and Kago are constantly fighting, but they are nonetheless protective of each other; Uto gets angry when somebody else deliberately provokes Kago and Kago gets angry when somebody scares Uto. They and their mother are clearly not all bad though since when Kala and the infant gorillas are almost knocked off the waterfall, all are quite dismayed, it clearly being an accident.
When Mama Gunda becomes Zugor's mate, Uto and Kago are presumably redeemed.
Role in the film
After having been abandoned by their old tribe for being too violent and too dim, they were chased into a canyon with their mother, believing themselves to be trapped by a monster.
When Uto found Tarzan, he instantly assumed that he was some sort of bird, and suggested throwing him off a cliff to make him fly. Kago turned down this idea, uninterested in something so small and weak, as well as pointing out Tarzan was not a bird, lacking feathers. However, both considered the idea that Tarzan was an ape absolutely ridiculous.
Later on, Uto caught Terk, and suggested throwing her off a cliff, but again Kago pointed out how stupid an idea this was, this time because Terk was a gorilla, as were they. When Mama Gunda finds out about Tarzan's tribe, she planned to overthrow Kerchak with her sons and take charge. They had to guard Terk from running away in the meantime, but she soon tricked them both and escaped.
Near the end of the movie, Uto caught one of the infant gorillas travelling with Kala, and suggested throwing him off the waterfall. Kala was angry and snarled, scaring him. The much more violent Kago stood up for his brother, easily intimidating Kala, but in the scuffle, Kala and the infants were accidentally knocked onto a dangerous ledge, to both Kago and Uto's dismay.
Uto and Kago then had to catch Tarzan to keep him from telling the tribe that they planned to take over. However, he proved far too small, quick-witted, and agile for them to catch and ended up giving them both quite a fright.
- Kago's sharp canines have grown in, meaning he is sexually mature, but he lacks the distinctive silver back, so he would be 9–11 years old - old enough to mate, but not to have his own herd.
- Uto's canines have not grown in, meaning he must be younger than Kago (female gorillas give birth about every 4 years); despite not having reached sexual maturity he is still larger, which would be why he doesn't submit to his older brother.
- It is not unknown for brother gorillas to work together to take over a herd in the wild, such as fighting a silverback who would overwhelm them on their own.
- Mama Gunda's idea for her boys to take over Kerchak's herd doubly enforces the moral of Tarzan II that we are stronger as a family, even if they are the bad guys at the time.
- "Kago" means "Stronghold" in Setswana.