zombies riding phantoms and other combos

The team has no idea how much the players are happy with the zombie horse added to survival and how will it upgrade the vanilla experience, I'd like to suggest other combos like zombies or skeletons riding phantoms, they could spawn with rare events or even as an easter egg, for example the phantom spawns when the player didn’t sleep for three nights then the zombie riding a phantom will spawn in the fifth night and the skeleton one would spawn at the seventh night or instead spawn in the caves below height y=-30. surprisingly witches riding phantoms is the perfect idea, I'd also suggest piglins riding ghasts for the nether.