The Alexander Horned Sphere is a special kind of shape that looks like a ball, but it's not just any ordinary ball. It's called the "Horned Sphere" because it has lots of little horns sticking out of it, like the horns on a bull or a deer.
Now, when we say "special kind of shape," we mean that it's actually a mathematical object. Mathematicians study shapes like this to learn more about them and the world around us.
One really interesting thing about the Alexander Horned Sphere is that it's impossible to untangle its horns from itself without cutting them off. It's like if you have a shoelace with knots in it - you can't untie the knots without cutting the shoelace.
Another cool fact is that the Alexander Horned Sphere is what's called a "non-orientable" shape. That means if you drew a little arrow on it to show which direction is "up," you could flip the shape over and the arrow would be pointing down instead. You can't do that with a regular ball or a cube or any other shape in our regular, 3-dimensional world.
So there you have it - the Alexander Horned Sphere is a special kind of ball with lots of little horns sticking out of it. It's a cool, non-orientable shape that mathematicians like to study because it has some tricky properties.