@HendrikVogt Of course! Otherwise it would spell "MATHZ". That's the American spelling of "MATHS" so, as an Englishman (though one who's a bit disappointed in his country's idea of "democracy" right now), I felt it my patriotic duty to invert the snake.

@AndrewStacey Oh, I didn't get the MATHS - nice idea! But I still don't see the "H" ...

@HendrikVogt Yes, I wasn't too happy with the H myself; I think it's the weakest one (even taking into account the fact that I had to invert the snake and the Dynkin diagram). It's the graph of x^2 - y^2 viewed from an angle to make it look a bit H-ish. If you have a better suggestion, let me know!

Couldn't help but remember the H-tree.

I guess that technically I need someone to ask how to do that on the main site before I can include it in my image; though I guess that the original H didn't come from a specific question.

Fortunately, this time I don't have to prompt someone to ask a question just so that I can post my code somewhere! It's a bit of a stretch, but I squeezed the code for the Htree in to an answer on binary trees (well, it is binary!).