Kinda funny.
Unlike some of the others I thought the credits joke thing was quite funny. But the actual animation was too short to be laughable at. The most I got was half a chuckle. It's like the punchline was longer than the lead up, and I'd expected a little better from Explosm...
Also, in the credits I noticed you wrote "By our book". A little unprofessional, right?
And I felt that there was too much to read and the credits dragged on for a while. I understand that that's the joke, but maybe you should have cut down on how many individual things you wrote and increased the staying time of each. That way, those who can't read as fast can actually read what there was.
Lastly, this makes the original Waiting for the Bus not funny any more either. I saw you mentioned a part 3 coming in the credits. Yeah... don't go ahead with that if you were serious.