give it a Protector and trade it
You need to trade a rhydon while it holds a protector item to make it evolve to rhyperior.
Make it hold Protector and trade it
Rhydon doesn't evolve by level. When the Protector is attached to Rhydon, trade it and it will evolve to Rhyperior.
At level 42, it will evolve into Rhydon. Anytime after it evolves into a Rhydon, make it hold a Solid Rock and trade it. When you're done trading, it should then evolve into a Rhyperior.
Rhydon evolves into... RHYPERIOR!!
Rhydon evolves into, ---------{rypherior}
Rhyhorn evolves into Rhydon at Level 42. Rhydon can then evolve by attaching a Protector to it and then trading it.
rhydon will only evolve if you make it hold protector and trade it.
Rhydon is not able to evolve in FireRed.
Rhydon, in Pokemon FR/LG, does not evolve.
Rhydon evolves when you trade it while holding a protector.
No, Rhydon doesn't evolve in Pokémon Sapphire.