Dragged amphibian, say (5)
I believe the answer is:
towed
'dragged' is the definition.
(towing is a kind of dragging)
'amphibian say' is the wordplay.
'amphibian' becomes 'toad' (toad is a kind of amphibian).
'say' shows a homophone (sound like).
'toad' sounds like 'TOWED'.
(Other definitions for towed that I've seen before include "Pulled along" , "drawn" , "Helped when powerless" , "Hauled" , "Dragged behind" .)