There's a Wikipedia page for "I've got your nose"

Everywhere, every day, babies get owned by this simple trick. I've got your nose is the practice of jokingly stealing children's noses — a timeless dad prank. It has its own Wikipedia article which describes it as an example of "teaching pro-social lying or playful deception to children." But goofy dads should be careful! The fig sign is a mildly obscene gesture in Mediterranean regions.