Some party themes would work really well with someone dressing up as the party characters.
For example, Elsa appearing at a Frozen Party would be delightful. And Spiderman attending a Superhero Party would bring a lot of excitement. Maybe even have a variety of characters attend the party. Other examples include CandyLand Characters, Bear, Animal Mascots for a Jungle Theme to name a fews.

Prices depend on the number of character chosen, and the type of activities they must perform. Can be further discussed.