Don Hertzfeldt is an American animator who is generally credited with the invention of "blood", a humorous, fictional substance which apparently fills the bodies of his nearly all his trademark stick-figure characters. In the Hertzfeldt universe, it is vital for the preservation of nearly every being (be it shaped like an ordinary person, or more like a grape or banana) that its "blood" never pours from its skin. However, it often does anyway, whether as a result of deliberate violence (an act as simple as ripping out a friend's stomach could be all it takes) or pure chance — and once the blood starts flowing, there's no predicting what comic shenanigans will ensue.
The Family Learning Channel, which currently employs Hertzfeldt as a public relations official, has extended the gag to many of its educational programs. For example, Ron Karlston, host of the game show "Genealogy-off", will frequently interrupt himself in an introductory monologue to stick a knife into his own wrist, which has, (unbeknownst to the audience) already been injected with the substance beforehand, than scream and collapse on the floor while yelling a catchphrase such as "Oh my god! My hand is 'bleeding'!" or "I'm a member of the vegetable family!"