Ogre with head lowered, seeing gigantic bird (3)
I believe the answer is:
roc
This could be a double definition.
'ogre' is the first definition.
(thesaurus)
'gigantic bird' is the second definition.
(I've seen this before)
'with head lowered seeing' is the link.
I am not very happy about this link. Some or all of it may belong to one of the definitions.
(Other definitions for roc that I've seen before include "Bird imagined" , "Sinbad's huge bird" , "Giant mythical bird" , "Mythical monstrous bird" , "Huge mythical bird of prey" .)