Is "Witten's Dog" from a Futurama episode an actual physics concept? 
In an old episode ("Mars University") of Futurama which is a TV show, a character named Professor Farnsworth was trying to lecture "Superdupersymmetric String Theory" and "Witten's Dog" to some other characters.
He wrote on board a Feynman diagram, the equation under the diagram looks very much like the electron capture mechanism: $p + e^- \rightarrow n + \nu_e$, except for that wavy underline. However, the Feynman-like diagram above does not look like the electron capture. Also is there any meaning to that caption:"Neutron encrusted steaming hot dark matter"?
Are any of the concepts reference in this chalkboard real physical concepts? If so, what are they?
 A: I would guess that the professor is explaining his/the(?) theory that dark matter is neutrinos, produced via a scattering process he calls "Witten's dog".  It is funny because the neutrinos are coming out of the dog's butt.  In the Standard Humor Classification, this is known as a "poop joke".
A: There is a Feynman diagram for particle scattering which looks like a dog... imagine each of the "tubes" in that picture shrunk to zero radius.
Like @dilaton says, this looks like a scattering (world sheet) diagram for closed strings. But with random (nonsensical?) particle operator insertions (maybe they're supposed to represent fleas?). And afaik, the moment somebody puts an energy scale like 93ev in a string theory calculation, you don't take it too seriously. :P
The equations and the electron capture (inverse beta decay) process written down might plausibly have physical relevance to the amount of neutrinos expected in the universe. I do not know enough details to comment on that.
A: Agree, It seems there is no physical meaning. Here is another link:
http://en.wikipedia.org/wiki/Mars_University
