There's a seam in German humour that is absurdist ... ("Two men are walking along the road; one enters a pasty shop, the other is called Lothar.") ... and simply defies explanation in terms of itself, because it isn't about the 'joke' but about jokes per se — it's an exercise in pure juxtaposition ... and an internally consistent punchline that made intrinsic sense would detract from that (if you were to 'get' the joke, you'd miss the point of it).
I think that Cow Tools is ... I'm not really sure how to put it into words, because all his stuff was absurdist/surrealist/dadaist ... but, if you see what I mean, more purely absurdist than his other output — maybe closer to Glen Baxter or Bernard Kliban than to Larson.
People get the joke when it's related to something they experience in their everyday life in some way: many people will have, at some stage in their life, driven past fields of animals, such as cows or sheep ... and even those living in cities will have noticed in their everyday experience of other animals, such as dogs and cats, that they don't stand on their hind legs as a rule ... so Larson's Car! doesn't need to be accompanied by intimate knowledge of the behaviour of cows specifically in order to laugh at the absurdity of it.
Confront them with Kliban's Chapter VI ... or a lot of Baxter's work (such as this one) ... and many (if not most) people just aren't going to understand why you laugh yourself into a state of incapacity upon seeing it.
I think that's where Cow Tools left a lot of (if not most) people scratching their heads in confusion as they sought a punchline that didn't actually exist.
As an aside, if you find Larson, Kliban and Baxter tickle your funnybone then I suspect you might (if you haven't already seen it) enjoy Green Wing — the show Scrubs aspires to be when it grows up.
I recommended it to a friend, who came back and made clear that he didn't find it remotely appealing but understood why I did: "because it's completely random."
It isn't, in fact, completely random ... but it is seriously absurdist (verging on surreal on more than one occasion). However, like a jigsaw puzzle, if you have the patience for it, it reveals itself to be completely coherent and as uncomplicated as Romeo And Juliet is at its core — and, if you have an appreciation of the Absurd, you will be rewarded with laughs almost constantly.
Which makes my point for me: for him, the juxtaposition of the absurdism with an otherwise inherently serious story was confusing and, as a result, he couldn't grasp that there was anything else to it ... that it was anything but random. but, actually, an exercise in meta absurdism — he just didn't 'get' it (Lothar just isn't a funny man, as far as he is concerned).
