The most common and most likely answer to this crossword clue is the 8 plus 4 letter word COWARDLY LION
I've seen this crossword clue in The Guardian
C
O
W
A
R
D
L
Y
L
I
O
N
More clues leading to the result COWARDLY LION
Buddy explains!
The straight part
We know that "He wanted bottle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case he wanted bottle = cowardly lion.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.