Singing telegrams are a great gift! Dave loved his 80th birthday telegram with a "homeless cousin" singing a special birthday song at the Saguaro national park gift shop for this Natl. park docent
Some options for characters are:
Clown - always hilarious and includes a special balloonhat
Gypsy fortune teller - palm reading and a song
Naughty nurse - we better check your pulse!
Ethnic Auntie - accents a specialty. Tia nana with pan dulce or Bubbe with the bagels + a song.
Homeless person etc.