Chris: ugly indeed (beaten only by the Death's Head HM we found here a couple of years ago, identified via The Net in the days when I still detested computers!) Btw we thought the horn was on top of the head till it started moving "backkwards" so to speak!
And Aristo: your WB picture reminds me of certain WC brushes.
Actually this moment we're chasing a hornet found in our recently vacated guest room, & C's particularly allergic to bites. A couple of summers ago we had several Asian Hornets nests in the village (originally imported in a shipload of Chinese pottery in Bordeaux).
Fire brigade no longer allowed to remove them: you have to call speciaist "troops". What I then found out about their bee-massacring abilities sent the proverbial shiver down my spine. Funny how we keep coming back to Natural History observations here, ennit?