So here’s the deal. In Shabbos 63 the Gemara criticizes those who have scary dogs on their property since it scares off those who would want to come collect.
This, however, is not to say that you can’t own anything dangerous. Just make sure it does not scare away visitors.
However, in Chulin 7b we find Rebbe Pinchas ben Yair complaining about a dangerous animal that Rabbeinu Hakadosh owned. Although Rebbe agreed to get rid of it, it is not clear if he agreed Al Pi Din or if that was just to satisfy Rebbe Pinchas ben Yair.
The Ben Ish Chai writes that obviously Rebbe wouldn’t keep dangerous animals. It must have been a gift from the king, and her had to keep it to honor the king.
There is a Chiyuv of לא תשים דמים בביתך.
So, draw your own conclusions.