Below are possible answers for the crossword clue 5 that's pretty insane, a cuckoo.
5 letter answer(s) to 5 that's pretty insane, a cuckoo
SPINY
having or covered with protective barbs or quills or spines or thorns or setae etc.; "a horse with a short bristly mane"; "bristly shrubs"; "burred fruits"; "setaceous whiskers"
having spines; "the dorsal fin is spinous"
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