Family grab unfortunate odd cook, tucking into snake (4,5)
I believe the answer is:
king cobra
'snake' is the definition.
(I know that king cobra is a type of cobra)
'family grab unfortunate odd cook tucking into' is the wordplay.
'family' becomes 'kin' (synonyms).
'unfortunate' indicates anagramming the letters.
'odd' indicates alternate letters.
'tucking into' indicates putting letters inside.
The alternate letters of 'cook' are 'co'.
'grab' anagrammed gives 'gbra'.
'gbra' placed around 'co' is 'gcobra'.
'kin'+'gcobra'='KING COBRA'
(Other definitions for king cobra that I've seen before include "hooded killer" , "Venomous type" , "Large venomous hooded snake" , "Large Asiatic snake" , "venomous customer" .)