h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I'd like permission to leave a clue here for the D.A. Detective agency to find, please.

You are given permission to leave a clue here, as long as it doesn't kill anything or disrupt normal operations.

*sets up a sentry gun to guard The Clue*

Thanks.

No problem really, ex-R

*throws in a dwarf with a target on its back*

*the sentry gun doesn't move*

Good, I can still do Dwarf Throwing practice .

*wonders where the CLUE is* *chucks anot her dwarf at the target*

It's gonna take a while. Sorry. I'm gonna put everything but fan clubs on hold till my head clears.

*takes down the saentry gun and waits for The Clue to be put down*

The mysterious figure drops off a box of explosives. One of the mercs takes delivery, and notices
a. the box has grungy dirt and cobwebs on it,
b. the crest of the h2g2 knights on it,
c. claw marks on the top, as if a skeletal hand was scratching it. He Curses and mutters something to the effect that he wishes suppliers wouldn't keep his explosives in graveyards.
A few weeks later, a portal opens up, and a group of intrepid souls step out. They are asking about a mysterious, cat-like figure. They are directed to
http://www.bbc.co.uk/dna/h2g2/classic/A730

OOPS!http://www.bbc.co.uk/dna/h2g2/classic/A730441

*pats the on the head, or at least tries to, but his hand falls through, and wishes her well* *places the sentry gun back up near the portals*

*connects the gun up so that it'll actually work when something comes near to it*

To get past the gun, go and look up the answer to this:

"Which animal walks on four legs in the morning, two in the afternoon and three in the evening?"