I re-rigged a "free resource" Horker Bull model from Skyrim to fit the Morrowind Horker skeleton. The upper arm-portion of the flippers is still a little weird, but I'll share it anyway. Working on the Horker Pup version, too...eventually.
Pretty sure the Horker Bull is still based off the vanilla Horker's model, so don't go posting it on Nexus or something.
Edit: Forgot the textures...drop the folder in the archive into Textures/horker. Mesh goes in Meshes/creatures/horker.