I am an outlier. I think the Moo/Foo mashup is the least of Mr. Sam's works. It is kind of obvious and has none of the really subtle but hilarious touches that make the rest of them so good.
This is the one many of us would like to see in real life-- these two "personalities", for lack of a kinder word, merged into one monster. The genius of it is that it absolutely has to happen, but never can. And it breaks my heart.