Weird sports I can imagine right now
1. UFC + Basketball
I believe I saw this, however, I don't know what rules they used. So it can be an octagon, two hoops, play goes 2 on 2, you have to break down the defense using martial arts, and do the shot.
2. American football + rodeo
I see it as regular American football, however, there could be a few beaters, on horses?????, and they are allowed to catch the runners using a lasso.
3. Football + prosthetic legs
Ah, that's the crazy one. Each player has a prosthetic leg in their hands, all the passing and shooting is done using this leg.
4. Hockey + curling
It will be a little of hockey, American football, and curling. So basically, the players have their hockey sticks, a much smaller curling stone, so they are pushing it toward the opposite team house, the defense tries to stop the pushers by blocking or intercepting the stone.
5. Ice skating + volleyball
Pretty simple, but very dangerous.
6. Waterpolo + American football
So regular water polo is more like a handball. But here the fun part would be having this "scrum" at the start of possession and basically the chasing of the runner.
7. Gymnastics rings + basketball
So I see it even more similar to Quidditch, the hoops are on a pretty big height, the protector/goalkeeper hangs on the gymnastics rings, constantly circulating between three of them, and the other players dribble the ball through a long field, once they passed the defense and are ready to make a shot, they are also using the rings to get higher and make a hit. Pretty complicated :)
8. Skateboard + basketball
The movements are done using skateboards. There are two hoops. Lower and higher. The one which is higher gives more points. There is a role on the team - kicker/trampoline carrier. This person can set the kicker for the teammate, so they can jump higher on the skateboard, making the slam dunk . You can make a skate trick to receive more points.
9. Fencing + treadmill
Oh, it's a funny one. Basically, you are fighting not only against the opponent but against the treadmill as well. So you have to make an effort to get closer to the opponent, to make a hit. Also, you can use the treadmill backward speaning for defensive moves.
10. Curling + baseball
The pitcher is located higher, on some platform, the pitcher pushes the curling stone down using the slope, and the hitter has to hit the stone as hard as they can to send it far far away. All the basemen and fielders are waiting on some platforms (and not on the field as in regular baseball) until the stone is hit by the hitter. They can intercept the sliding stone with their sticks while sitting on the platform. Once the stone is sent into the field by the hitter, the game goes quite similar to baseball.