Patrick Williams wrote:

Could it be a battering ram?

Based on the representations of battering rams I’ve seen in heraldry with actual rams’ heads at the end (thus, presumably, the origin of the term), I don’t think so.

Joseph McMillan wrote:

I wonder if perhaps it isn’t an eagle at all but a vulture, and the bald spot meant to indicate the vulture’s hairless head.  It doesn’t look very much like a vulture, but for some reason the thought comes to mind.

I’ve seen some representations of vultures in heraldry that don’t look very vulture-like; indeed, they look close to eagles, as is also the case with pelicans.  The idea of vultures being bald seems to come no earlier than the 19th century.