Lissy says:

Men who are attracted to older women are often called “cougar hunters” or “cougar chasers.” The term “cougar” typically refers to an older woman who is attracted to and pursues relationships with younger men. Conversely, men who are attracted to older women may also be referred to as “cubs” in reference to the younger counterpart of a cougar. These terms are somewhat informal and can vary in usage and perception depending on cultural contexts and individual preferences.