I have done some tests to see which mobs are compatible with the Ride-able Spiders Mod (allows players to tame and ride spiders) And here are the mobs who are compatible with this mod.
- Jumping Spider
- Money Spider
Although these mobs are compatible with the mod, the spider saddle and armor (Items from the mod) do not show up on the spiders' models due to them being different than that of your average everyday spider from vanilla minecraft. But does it matter at all? I enjoy taming Jumping spiders and having some fun. :D