Snake in den is weird, peculiar
I believe the answer is:
sidewinder
'snake' is the definition.
(sidewinder is a kind of snake)
'den is weird peculiar' is the wordplay.
'peculiar' indicates anagramming the letters.
'den'+'is'+'weird'='denisweird'
'denisweird' is an anagram of 'SIDEWINDER'.
'in' is the link.
(Other definitions for sidewinder that I've seen before include "Rattlesnake - air-to-air missile" , "Rattlesnake; misile" , "Burrowing snake" , "Rattlesnake with distinctive motion" , "rattling creature" .)