The most common and most likely answer to this crossword clue is the 9 letter word SASQUATCH
I've seen this crossword clue in Independent
S
A
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Q
U
A
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C
H
More clues leading to the result SASQUATCH
- Hairy giant has an unauthorised dwelling in school
- Imagined primate crouching in school
- Don’t speak about a stocky cryptid’s origin – man in gorilla suit probably?
- ‘Bigfoot’ crouching low in school
- Monster taps letters on it low down
- Beast reportedly seen in South Africa by short and stocky child
- Trapped inside school, a dumpy hairy creature
- Squash cat; poor furry creature
- Monster incorporating bit of aerobic exercise into school
Buddy explains!

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 SASQUATCH mean?
SASQUATCH noun- A large hairy humanoid creature of western North America; a Bigfoot.