SB, it’s “Beeblebrox”, not “Beetlebrox”. May I ask where you found that answer?
Zaphod Beeblebrox is a character in the radio comedy series “The Hitch-Hiker’s Guide to the Galaxy”. He has two heads. The series went on to spawn a series of novels. There’s a lovely scene in one of them,, in which Zaphod goes to bed and one of his heads goes to sleep, whilst the other stays awake and does crosswords!
We too found this one challenging, and not always in a good way. We’re stuck on two:
12d: Fabric made of net, good, strong thing all round (4-3). We have G - - - / T - X. It looks like GORE-TEX, but we have no idea why.
14a: Glass that’s filled behind agent’s back (6). We have - U - P - -.
All help gratefully received!