Pet alone upset graceful creature (8)
I believe the answer is:
antelope
'graceful creature' is the definition.
'antelope' can be an answer for 'creature' (type of animal). I am not certain of the 'graceful' bit.
'pet alone upset' is the wordplay.
'upset' is an anagram indicator.
'pet'+'alone'='petalone'
'petalone' with letters rearranged gives 'ANTELOPE'.
Can you help me to learn more?
(Other definitions for antelope that I've seen before include "Such as a gnu or eland" , "eg Eland" , "Reebok perhaps" , "A lone pet as a ruminant" , "Fast runner" .)