Perhaps it is because of the illustration on 8 and 46, but the image of Grendel was very closely tied to the trolls of the Elder Scrolls. No physical description is given of Grendel, aside from appearing unnatural, showing up at night and eating people. The last part is what links Grendel to the trolls. Trolls are often found with bones around their “nests” and implies that they eat people. Grendel probably would have had a a physique similar to these trolls to have grabbed and carried the soldiers off to his cave.
This is my interpretation of Grendel. Grendel’s appearance is never described in the poem, so how is it that my image of him is the troll? The image of Grendel would be different from everybody. My experiences, namely the Elder Scrolls, have given me an idea of what monsters look like, thus when a monster is not described, I relate it to something that is familiar.
Just as a side note, The Elder Scrolls V: Skyrim (a video game) could have easily turned into Beowulf if those chose. The setting, many of the names and narrative the game has puts in very close proximity of becoming Beowulf. Heck, one of the locations is named Hrothgar.