If the gossip between nearby npcs is to be believed heatran is hidden around Jaune plaza. They also mention mimicking the cries of pokemon. This is driving me crazy and could literally be nothing but I've had some ideas.

Jaune was France' pokemon yellow and so I'm pretty sure the pokemon to mimic is pikachu. is there a way to quick use pokemon calls? I've tried the pokedex and have spoken into the mic several times with no luck. anyone else have any ideas?