Sapata used to be a trick Tokota forced to perform tricks at a circus and thus was deemed 'The Dancing Bear' which is the meaning behind her name, as her -then- handler thought it to be funny and ironic. 

She is very docile mannered, sweet and patient however is extremely protective of her handler, and saviour, as he paid handsomely to cover her release from the cruel conditions she was forced to live in. Despite how aggressive her handler appears, Sapata always knows that she is completly save with him and that he is all bark and no bite, often being the only one who can reason with him.