The most common and most likely answer to this crossword clue is the 7 letter word GORILLA
I've seen this crossword clue in The Times
G
O
R
I
L
L
A
More clues leading to the result GORILLA
- Go by stream with a fierce guy
- Primate's a partisan, it’s said
- A lot of blood over area surrounding sick animal
- Large creature seen in stream in Indian state
- Travel, coming to stream, by which sits a wild animal
- Primate runs with difficulty in part of India
- Somewhat ailing or ill, a primate
- Great ape is right poorly in Indian state
- Outside entrance to Oratory, interrogate a primate
- Primate received, at first, poorly in Indian state
Buddy explains!

The straight part
We know that "animal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case animal = gorilla.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GORILLA mean?
GORILLA noun- The largest of the apes, native to the forests of central Africa, and known for their trait of knuckle-walking.
- A big and brutish man or a thug; a goon or ruffian.
- A powerful person or organization; a heavyweight or behemoth.