[Soundgod]

You know there's a story (told by Marty Sklar) about the time they previewed the original Abe Lincoln animatronic at the 1964 World's Fair for some big wigs before the fair opened and one of Abe's hydraulic lines sprung a leak. So here's Lincoln shooting red fluid and the big wigs loved it because they thought it was supposed to be blood.
After that, all animatronics use a clear hydraulic fluid.