In English, "怪人" can be translated as "weirdo" or "oddball". The term comes from the English word "weird", which means strange or unusual. Some example sentences and their translations are:

"That guy is such a 怪人 - he always wears a hat made out of tin foil!" (Translation: "That guy is such a weirdo - he always wears a hat made out of tin foil!")

"My neighbor is a 怪人 - he never leaves his house and just plays the same song on repeat all day long." (Translation: "My neighbor is a weirdo - he never leaves his house and just plays the same song on repeat all day long.")

"I used to think my coworker was a 怪人, but now I understand that he's just really socially awkward." (Translation: "I used to think my coworker was a weirdo, but now I understand that he's just really socially awkward.")