Child's toy rodent talked oddly (6)
I believe the answer is:
rattle
'child's toy' is the definition.
(I've seen this before)
'rodent talked oddly' is the wordplay.
'rodent' becomes 'rat' (rat is a kind of rodent).
'oddly' indicates alternate letters (letters in the odd-numbered positions are used).
The alternating letters of 'talked' are 'tle'.
'rat'+'tle'='RATTLE'
(Other definitions for rattle that I've seen before include "Make worried, baby's toy" , "cause nervousness" , "Venomous creature's warning" , "Noisy type of snake" , "Disconcert - English conductor, b. 1955" .)