An expression of emotion, usually when something light-heartedly upsetting is happening.
Also, "holy cat-hair, man" may be used when desired.
1) Joe goes to the refrigerator for some milk. He finds an empty carton. He says "Holy Cat-hair, who drank all the milk?!?"
2) Susie and Jane meet for a movie. They find they are wearing the same outfit! They say to each other, "Holy cat-hair man, you're wearing my outfit!!?!"