Most likely the gorillas.
The crocodile could win, but would get badly injured by the ox and the cattlebeast's body.
Some dogs will get the cattlebeast by distracting it and others will go behind to bite out the hamstrings. If the dogs avoided the horns and the hooves, the dogs will get the cattlebeast at the end.
It's likely the gorillas may win this fight. The reason being is that the dogs will attack the cow (or bull) from all sides, a couple distracting from the front and the others closing in from the back. When the cattlebeast is down and no longer able to fight, then the dogs take on the gorillas. However, a couple of male gorillas will be more than what the five dogs expected, resulting in them either being pelted to death by the rocks and sticks thrown by the gorillas, or chased off by the bluff charges.
Possibly the gorillas, but fights between these two animals are very rare since gorillas and oxen are herbivores and will leave each other alone.
It is likely that the hippo would win this fight. The 5 dogs would not be surprised that the gorillas would kill them by either hiting them with stones and sticks. When the 2 gorillas defeated the dogs by throwing sticks, the 2 gorillas may throw stones at the hippo, but this would only make it want to fight more. The hippo would come to grab the gorillas with its large jaws and crunch them to death.
The gorilla will defeat the cattle-beast easily because the gorilla is more suited when it can stand and grab things.
There are just too many variables to this question to be able to answer, simply because there are more animals involved than can be justified in a normal "who-would-win" question.
Most likely the 5 gorillas will win. After the ox fights the 10 dogs, it would be killed by the dogs. Then, the gorillas can kill the dogs easily by charging at them or grabbing and throwing sticks or stones at them.
The 15 gorillas because they would all throw heavy stones at the elephant.
Bear. Bears are predatory by nature. Gorillas are not, and thus can be seen as prey by a bear.
gorilla because it would grab it and slam it into the ground
Dogs that get into a pack, especially those from neighboring areas, will band together to kill livestock. One cow or bull may get seriously hurt from a pack of dogs, especially if the animal doesn't have any place to protect its rear end.