In Clash of the Titans (2010), Perseus finds a metal owl.
It's obviously some sort of in-joke, but what's the reference?
The reference is to the original movie Clash of the Titans from 1981. The owl has a more prominent role in that movie. This is just a "cameo" to give the audience a chuckle.
Edit: Its name is Bubo ... I never knew it had a name, but the wiki page explains it all!