Modder Snoopey has developed a mod that turns the mudcrabs in Skyrim into Dr. Zoidberg.
To those that are not familiar with that name, Dr. Zoidberg is the lobster-like alien who is also the staff doctor in the Futurama cartoon series.
This and the swearing mudcrab mod has made the mudcrabs the most hilarious enemies in Skyrim.
This mod does not only change the skin of the mudcrabs but also includes quotes from the character. You can get the mod here.