Hey, I found this really awesome Etsy listing at https://www.etsy.com/listing/184191330/curious-george-birthday-party-sign-in
Curious George Party Monkey Juice
Curious George Clip Art | Curious George DIY Birthday Party- Invitations
Curious George Party
Photo 2 of 20: Curious George / Birthday "Dane's Curious George Birthday Party " | Catch My Party
Maybe use this image but make the balloons be guest finger prints... for a guest book?
Don't Worry, Be Scrappy: A Curious George Party (Charlotte's 2nd Birthday)
Curious George Party- Games & Activities