The scary old man is bulky, with long arms, pale blue skin with darker blue spots, yellow eyes, and only has one tooth in his mouth, although it fell out later on, therefore rendering him toothless.
The scary old man is an intimidating and eccentric man, living in isolation. However, he is still kind, helpful, and has no problem with accommodating strangers. He appears to be cheerful and friendly most of the time, even when someone makes fun of his appearance and acknowledges his weird behaviour. He also cares deeply about his mother, and does not tolerate any insults or mockery directed at her.
According to early storyboards of "The Vacation," he was intended to be a goblin-like figure.