It's the 'Cuteness Attack' theme, and the cat header is the default. You can then change its face, but I can't find an option to remove the cat completely. You're most likely going to have to do a little CSS editing to get rid of it.

If the fixed background/scrolling journal entries is what's interesting you, then try out different layouts because some may also have that feature. Mess around with yours too!

And I thought the list was pretty long. ;p