This can be a way to obtain these Pokemon without trades so I was just wondering if any source has concrete numbers. NOT for how often golbat calls, but what Pokemon will appear when it calls
Haunter can call Gengar
In Malie Garden, Politoed has a 1% chance of being called at night during rain.
Slowking can be called by Slowpoke only at Kala'e Bay.
Clampearl can call Huntail at night, or Gorebyss during the day.
These are the only Pokémon that can be called for help that evolve by trade.