To get on the skeleton horse, you have to be holding a golden carrot, then tame the horse and put a saddle on. The zombie horses don’t spawn in minecraft pocket edition unless the player spawns them manually. Undead horses can spawn naturally, you don’t have to use eggs. They just need to be struck by lightning.
Skeleton horses spawn only from “skeleton traps”. A “skeleton trap” horse is a skeleton horse spawned from a fraction of lightning strikes during a thunderstorm or by chance (0.75–1.5% chance on Easy, 1.5–4% on Normal, and 2.25–6.75% on Hard, depending on regional difficulty).
Skeleton horses should behave like skeletons (Burn in the sun & despawn quicker in the day) … The only way to find/ capture a skeleton horse is if a living one gets struck by lightning.
You can summon a lightning bolt whenever you want using a cheat (game command) in Minecraft. This is done using the /summon command.
Baby zombie horses can be spawned, too. They do not burn during sunlight.
The rarest regular spawning horse is easily the skeleton horse…
A lightning strike affects certain mobs differently: Lightning may randomly spawn a “Skeleton Trap” Horse with a chance of 0.75–1.5% chance on Easy, 1.5–4% on Normal, and 2.8125–6.75% on Hard, depending on the regional difficulty. … A pig struck by lightning turns into a zombified piglin. A creeper becomes charged.
How to Enter the Command