"Kao-anis" were little animations bouncing up and down to look like they are floating, and used as smilies on internet forums/boards in the 2000s.

Many kao-anis based on Catsuka's mascots were created to be used on Catsuka Forum.
The first batch was made by Anneko.

Kao-anis by Anneko




Kao-anis by Den X



Kao-anis by Koneko



Kao-anis by Chron



Kao-anis by The Buzz



Kao-anis by Mecanic



Kao-ani by Ganesh



Kao-ani by Pierrot666



Kao-anis by Mechass



Kao-anis by Joel Jurion