Ray’s the chap getting the thanks (5)
I believe the answer is:
manta
'ray's' is the definition.
(manta is a kind of ray)
'the chap getting the thanks' is the wordplay.
'the chap' becomes 'man' (I've seen this before).
'getting' means one lot of letters go next to another.
'the thanks' becomes 'ta' (UK informal version of 'thank you').
'man'+'ta'='MANTA'
(Other definitions for manta that I've seen before include "Devilfish" , "Giant ray" , "Kind of ray" , "Large ray" .)