When I was 18 I had a CB Radio and I had the handle Ratcatcher after a characyter from the DC Batman comics.
Anyway, when I got into the Internet my ISP at the time had an 8 letter restriction on logon names so I shortened it to Ratcat and for there a whole new idea of the persona emerged.
The idea of the Rat and the Cat mixture is quite new, previously it was all Rat.
Also, it has NOTHING to do with the Australia 80/90's band called Ratcat.
When I first signed in for a forum, the one at TF.N, I never realised I 'needed' an nickname. So I thought one up, I like q's since Dutch doesn't use them much. I made queeq, and then later I was reminded the back-up computer on Red Dwarf was called "queeg". I must have stored that name somewhere in the back of my head. Anyway, it's "queeq" with q's.