Different model packs?

I'm not sure if this is the right forum, but anyways...there are several images that appear on the top left of the Doomworld website, one of which is of a 3-D mancubus. It looks a lot different than the mancubus I see in the model pack I downloaded for Risen 3-D and Doomsday. Is there another model pack I'm unaware of?

You mean this one



Although the gif files are called mancsketch, it's actually a photo of a real 3D model of a mancubus used by id during Doom2 development. The picture is most probably a scan from "The Book of Id" that comes with the "Id Anthology" Box set of games.