The most common and most likely answer to this crossword clue is the 8 letter word CREATORS
C
R
E
A
T
O
R
S
Buddy explains!
The straight part
We know that "They form" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they form = creators.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 CREATORS mean?
CREATORS noun- Something or someone which creates or makes something.
- (social media) Ellipsis of content creator, someone who regularly produces and publishes content on social media, especially of a monetizable nature.
- (sometimes capitalized) The deity that created the world.