I dunno, is it really important to you to have such a username? Does it matter what anyone else says about it? It's not inherently offensive so it's not like you have to change it. But if you don't feel happy with it change it. IMO NoobClock sounds better and is less likely to be misconstrued.
Anonymous-Frog
NoobClock almost sounds like Clock Crew, while NoobJew rolls off the tongue better.
Also if anything, it's the 'noob' part that needs changing.