Prised off creepy-crawly (6)
I believe the answer is:
spider
'creepy-crawly' is the definition.
(spider is a kind of invertebrate)
'prised off' is the wordplay.
'off' indicates an anagram.
'prised' anagrammed gives 'SPIDER'.
(Other definitions for spider that I've seen before include "Prised open the arachnid" , "Flycatcher?" , "Arachnid - snooker rest" , "potter's accessory?" , "Prised out the 8-legged creature" .)