What Pokemon are rivals according to PokeDex entries? For example, I know that Zangoose and Seviper are enemies, or Heatmor and Durant. Are there any other Pokemon like that?
Other rivalries that I can remember seeing would be between Persian/Meowth and Murkrow/Honchkrow, their dex entries stating that they've been known to steal each others treasures. Others by entry would be Kyogre and Groudon (of course), technically Cressilia and Darkrai since one creates nightmares while the other wards them off. Wurmple and Swellow are rivals since one hunts down the other as prey.