Mew as Pwnyta said.
Meinshao and Medicham can do: Calm-mind, Bulk-up, Baton-pass, and Endure holding Salac berry
Other Pokemon that can raise alot of Stats
Mr. Mime: Iron-defense, Calm-mind, and Baton pass
Masquerein and Venomoth as Pwnyta said
Blazekin: Hone-claws and or Bulk-up, Baton-pass, and he has Speed-boost and Agility
Girafarig and Leavanny: Calm-mind, Agility, and Baton-pass
Floatzel: Bulk-up, Agility, Baton-pass