Tiny, disgusting tailless creepy-crawly (6)
I believe the answer is:
weevil
'creepy-crawly' is the definition.
(weevil is a kind of invertebrate)
'tiny disgusting tailless' is the wordplay.
'tiny' becomes 'wee' (I've seen this before).
'disgusting' becomes 'vile' (I've seen this before).
'tailless' means to remove the last letter.
'vile' with its last letter taken away is 'vil'.
'wee'+'vil'='WEEVIL'
(Other definitions for weevil that I've seen before include "Type of beetle that feeds of stored grain etc" , "Insect that feeds on plant products" , "Insect pest that damages crops" , "Small beetle with a long snout" , "Small beetle, pest of crops" .)