if you mount a horse then mount another horse without getting off the first one , the second horse you mount will have double the normal health
see 7:27 of this video https://www.youtube.com/watch?v=N4q2wzJhyH8
Linked issues
Comments 3
Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Duplicate of MC-14097.
Cannot reproduce.
Note that bred horses can have up to 26 hearts (or even more)