Lionel Van Helsing was Dracula's best friend back in the day. He wanted to kill Dracula because Dracula married the girl of his dreams, Tanya, who he instantly fell in love with when he bumped into her on the street, and she thought he was going to rob her, so she knocked him out. When he came to, he found Dracula had made his move on her. He appeared in "Dracula Must Die!".
Lionel is African-American, has a big black hat to match his suit, a fluffy white beard, and white gloves. In the 70s he had an afro and colorful clothes.
In the 70s, Van Helsing and Dracula were best friends. As seen in a flashback, they enjoyed the same ice cream, worked a teddy bear factory, and went out dancing and eating pepperoni pizza. Grim, Billy, and Mandy validate this by finding matching friendship bracelets on Van Helsing and Dracula. Van Helsing tells them he promised to keep wearing his until he killed Dracula.
However, he later decided against it after Tanya bursts into the warehouse they were in. It's revealed that Tanya's son, Dick, is half vampire and half human while his sons, Irwin and Melvin, are half mummy, one quarter vampire and only one quarter human. After seeing how Tanya now looks and treats him, as well as how miserable Dracula is with his nerdish offspring, Lionel realizes that he's actually better off than Dracula, and struts out of the warehouse as Dracula begs him to destroy him but is ignored.