The most common and most likely answer to this crossword clue is the 9 plus 9 plus 6 letter word BRAZILIAN WANDERING SPIDER
I've seen this crossword clue in The Guardian
B
R
A
Z
I
L
I
A
N
W
A
N
D
E
R
I
N
G
S
P
I
D
E
R
Buddy explains!
The straight part
We know that "Creepy-crawly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case creepy-crawly = brazilian wandering spider.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.