By Klono's carborundrum claws! (It had to be said.)

Apostate! Heretic!

It's carballoy claws (or "curving carballoy claws") in the canon.

Seriously, I got curious and did a quick text search. Here are the phrases used in the books....

Holy Klono
For the love of Klono
Klono's brazen whiskers
Klono's own gadolinium guts
great Klono
I'm Klono's maiden aunt
I wish to Klono
By Klono and all his cubs
Great Klono's tungsten teeth
Klono's brazen hoofs and diamond-tipped horns!
the teeth and claws of holy old Klono himself
the curse of Klono
Klono's whiskers!
Holy Klono's Indium Intestines!
Klono's carballoy claws
By Klono's tungsten teeth
Holy Klono's brazen tendons!
Holy Klono's claws!
by Klono's prehensile tail!
Klono's curly whiskers!
Klono's golden grin
Klono's golden gills!
Holy Klono's gadolinium guts!
Holy-Klono's-claws!
just as sure as Klono has got teeth and claws.
by Klono's emerald-filled gizzard,
you'll wish to Klono you'd never been born
KLONO'S tungsten TEETH and CURVING CARBALLOY CLAWS!!!
as safe as if you were in Klono's hip pocket