What is the collective noun for brumbies?

There isn't a widely accepted collective noun specifically for brumbies.

Here's why:

* Brumbies are feral horses. They're not a distinct species, just wild horses that originated from domestic horses.

* Collective nouns are often based on species. For example, a flock of birds, a herd of elephants, etc. Since brumbies are simply feral horses, they share the same collective nouns as domestic horses, like "herd," "band," or "mob."

So, while there's no specific term for a group of brumbies, you can still use the common collective nouns for horses.