At first glance it looks like a fragment of the typical
horse fibula, which was apparently centred in the middle Danube region and dates 2nd - 3rd c AD. The size is right too.
However, yours looks to be in the round/3-D. The usual
horse fibula has a flat back.
There is also a 3-D
horse fibula - I think there are images on the wiki - which is derived from the knee
type and has a wide
spring at the rear feet/tail
area. They were found in the Pannonias (similar dates). Might be a fragment of that. Could also be a small statue.
A front or 45 degree view might
help.
Shawn