I have so many characters in this series now that i have to keep a list of them! Hmm. Uncle Bob in space. Hmm!
I have heard another meaning for the fubar acro: fouled up beyond all recognition.
But in this case, the 'foo' in foobear means exactly the same as the 'foo' in foo-ighters. 'Foo' was a popular term in American culture in the 1930's, derived from the comic strip Smokey Stover, who drove a foomobile fire engine with only two wheels. At that time it was often used to signify a goofy or strange technology, or a goofy or strange social custom.
The term 'foo' was borrowed by a radar operator in the 415th Night Fighter Squadron in WWII, who was a great fan of Smokey Stover and his favorite phrase in the comics, 'Where there's foo, there's fire!' It was that radar operator that gave the name foo-fighters to the strange, apparently way-too-fast or maneuverable aircraft seen sometimes on his radar screen, or chased by fighters of his wing, mostly at night. The term later became a generic for any UFO.
For Max and his crowd, a loose ball of energy that can cause mischief is definitely a foo!