The animals? Well, within the city walls there are rabbits and cats that are... unusually vicious, with teeth they're not afraid to use, so watch out for them.

There are more dangerous creatures out in the Wastes. A lot of sand worms.

As for the Animus--well, I'm not the best person to ask--but they're the spirits who control who here comes and goes, as well as causing things called "events" periodically.