Unexpectedly greet a creature (5)
I believe the answer is:
egret
'a creature' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'unexpectedly greet' is the wordplay.
'unexpectedly' indicates anagramming the letters.
'greet' is an anagram of 'EGRET'.
Can you help me to learn more?
(Other definitions for egret that I've seen before include "Type of forty eight Ac" , "(Usually) white heron" , "Wader with white plumage" , "Kind of white heron - greet it" , "Wading bird like a heron" .)