Were there any fairy tale characters that were planned to be inclued in the first Shrek film , but did n't make the cut ?
There were also two holiday specials called " Shrek the Halls " and " Scared Shrekless " , a spin - off called " Puss in Boots " ( a prequel to the Shrek series , exploring Puss 's origin story and his life prior to meeting Shrek and Donkey ) and several shorts .