I've got the idea of playing both as a creator and their creation, namely a spooky girl based on Sadako Yamamura from [i]Ring[/i].

The joke would be that 'Sadako' would constantly be creeping up on people unintentionally, just wanting to make friends but scaring people all the time until they got used to her. This would be particularly annoying for her creator, who had been a screenwriter making the character for a cheap horror film based off a successful doujin they'd made while in high school, with 'Sadako' based on a girl they'd had a crush on at the time.