Animal firm yet unsteady incubating egg (6)
I believe the answer is:
coyote
'animal' is the definition.
(I've seen this before)
'firm yet unsteady incubating egg' is the wordplay.
I cannot really see how this works, but
'firm' could be 'co' (a firm is a company) and 'co' is found in the answer.
'egg' could be 'o' (I've seen this in other clues) and 'o' is found within the answer.
an anagram of 'yet' is 'yte' which is located in the left over letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for coyote that I've seen before include "Small wild dog" , "Small N. American wolf" , "predatory creature" , "Prairie-wolf" , "Wolf-like animal" .)