In the past I've changed it to rude things, currently though I'm trying not to do that as I want to be able for visitors to read what I've written with a clear concious. I tend to go for animal sounds too though sometimes I just go for something a little scary like "I see dead people".
For Juri (or Julie) I went with "Hello Baby" and his end catchphrase I changed to Hoo-hoo, as his original was not rude but just a bit blunt. "Ne, kimi" which is like saying "Hey, you."
The animals in NL though are asking all the time so sometimes I just keep what I originally changed it to.
Bazinga