A tragic hero is a character in a story who is really important and admirable but has a major flaw that causes their downfall.
Imagine you have a favorite superhero, like Spiderman. Spiderman is really strong and brave and always tries to save the day. He's a hero and everyone looks up to him.
But let's say Spiderman has a flaw where he struggles with anger and sometimes makes really bad decisions because of it. Maybe he even hurts people unintentionally.
Even though Spiderman is still a hero, this flaw can lead to his downfall. Maybe he loses his job, friends or his powers because of it.
That's a tragic hero. Someone who is great, but because of a flaw, messes up in a really bad way that leads to their downfall.