3. Saelt-Marae (Yak Face)
What you see in the films: Much like our pal Hammerhead, Yak Face was this character's production nickname, and the name that appeared on his 1985 action figure that Kenner didn't release in the United States, sending completists into a rage. He was part of Jabba's crew in Return of the Jedi, and was present on the sail barge in the Sarlacc Pit scene.
The expanded backstory: Saelt-Marae is a high-level information broker, which is apparently even shadier than it sounds. He's been an informant to both the Republic and the Empire, and was acting as an informant to Jabba the Hutt during the time of Return of the Jedi. He posed as a common merchant, and mingled among Jabba's minions to learn of any potential secret plots against him. Here's the convoluted part: Saelt-Marae's journals contained much information about his personal and business contacts, information he could use for bribery or blackmail. It also contained a detailed account of his 200 year courtship of his chosen mate. That's right- Saelt-Marae dated (a female Yak Face?) for 200 years before they mated. Things must be much easier now, in the age of dating sites like YakMatch.com.