Ox
The titular character of the chap book is accused of murder. Through his actions, a human died, which brought him before the animal court. His story of suffering and insanity contains the main moral of the story, namely that animal abuse is inherently evil.
Dogs
The dogs, while they only appear on the first page, are interesting characters. They are the embodiment of thieving and mischievous characters that would do anything to get ahead. They are the ones that bring the ox before the court in the first place, hoping for some kind of bounty. However, their character is questioned and they are refused to stand as witnesses. This is an acute observation of court trials of the time of publishing. People who were considered to be of ill repute often were refused as they could not be trusted.
Lion
As in most fables, modern animal fairy tales and popular fiction the lion is the leader of the animal kingdom. In this case he is the judge whose ruling is absolute. The story offers little insight into the character of the lion, only that he is a fair and wise leader. He is described as a kind character that interrogates witnesses in a way that makes them feel at ease. His helper the bear has similar qualities. Considering the real animals these characters are based on, such a gentle and wise nature is unusual.
Horse and Ass
These two characters only appear at the beginning of the trial and are depicted as a couple. They represent the animals in the husbandry industry, those that are in service to humanity. At first their account condemns their brother the ox, however they are also moved by his sad tale. In the end, they are being reminded of the hardships their daily life entails, further condemning humanity.
Bee
The bee is an interesting choice for this character. It is the silent witness that has seen the whole incident, not just the murder itself. In a lengthy, emotional description the bee pleads for the ox, showing that his actions could not be his fault. Weirdly enough, the bee is described as male (using he) and as serving the queen. Biologically, this is incorrect, as only female bees collect food and pollen. This can be seen as either a ignorance of the time or bias towards male characters.
Tiger
The final important character of the book is the tiger. He is not mentioned till the bee has given his evidence. However, at this point the tiger seems to occupy the position of a lawyer, giving the final plea in defense of the ox. It is the tiger who frames the moral of the story, reminding the other animals of the cruelty of men on their kind. Similarly to the lion, the tiger is a kind and wise creature that shows no malicious intent.