Waldemar, played by Jeffrey Tambor, is a character in the film Saturday the 14th.
Waldemar and Yolanda are a pair of vampires who are interested in buying the old Hyatt House on 329 Elm Street. They are only interested in order to acquire the Book of Evil. However, the Hyatt family inherit it in a will and move in before they are able to purchase it.
Waldemar sneaks into the house by turning into a bat. The Hyatts call the exterminator who sends Van Helsing to exterminate the bats. Van Helsing is actually after the book for himself. Van Helsing fights Waldemar and Yolanda over control of the book.
As it turns out Van Helsing wants to book to rule the world and Waldemar and Yolanda were trying to prevent that from happening. They manage to stop him and get to keep the house.