You might be able to.
You'd be best to call in advance and make a reservation.
Either way, it's about $60 per person, and will include a LOT more than possibly seeing a character with his head off. It's a LOT of information about the history and creation of the park, as well as how the park runs on a daily basis. It also includes lunch at the Columbia Harbor House.
Also, you must be 16 or older in order to take this tour.