To make up for the lack of a monthly event this month everyone gets a free Zombie and/or Skeleton horse!
they have 26 hearts of health, can't be armored or leashed.
Judicial ranks do the command (You can copy it from here)
/summon EntityHorse ~ ~ ~ {Type:3,Tame:1}
For a tamed Zombie horse
or
/summon EntityHorse ~ ~ ~ {Type:4,Tame:1}
For a Skeleton one
Then spawn in a saddle for the player.

Happy Creepy horses everyone!