Beginner English with spooky Halloween decorations

What is a jack-o'-lantern in English?

A jack-o'-lantern is a pumpkin with a face cut into it. People take out the inside, cut eyes and a mouth, and put a light inside. At night the face glows. People make them for Halloween, a fall holiday in the United States. The name is old. Long ago in Ireland and Britain, people cut faces into other vegetables, not pumpkins, and made the same kind of light.

In the clip the person sees one and says “Look, a pumpkin. A jacko’lantern. An evil jacko’lantern.” A scary face is a normal style for a jack-o'-lantern. You say it like “jack-oh-lantern.”