On the one hand, Grendel points out the ways in which he is definitely dissimilar from the ram. His first point of difference is the way thet he says his brains are definitely not, "squeezed shut, like the ram's, by the roots of horns." Grendel is disgusted by the lack of "dignity" possessed by the ram, in particular focusing on the ram's sexual drive and his "mindless ache to mount whatever happens near." However, the next paragraph focuses on the points of similarity between the two figures. Notice how Grendel describes himself as little better than an animal:
Not, of course, that I fool myself with thoughts that I'm more noble. Pointless, ridiculous monster crouched in the shadows, stinking of dead men, murdered children, martyred cows.
He clearly depicts himself in this sense as being little better than the ram which he compares himself so disfavourably with. On the one hand, therefore, Grendel has the intellilgence and capacity to reason that separates him from the ram. On the other hand, his appearance and deeds means that he has to hide away and become a "pointless, ridiculous monster."