Minecraft wiki entry for Development_versions, associated text: A new passive mob that spawns in the Nether on lava oceans.
Can be saddled and controlled with warped fungus on a stick.
Is damaged by water and rain.
Can be bred with warped fungi.
Can spawn with zombified piglins or baby striders riding them.
If they spawn with a zombified piglin, they will also have a saddle equipped.