Catfishing is when someone pretends to be someone else online. A catfish might pretend to be someone older or younger, a different gender, or even a completely different person. They often do this by creating fake profiles on social media sites, dating apps, and other websites. Catfishers usually ask for money, try to get something out of the person they are catfishing, or use pictures of other people to trick people into believing they're someone else.