Gonna compile a list of all of the NPC Partner Pokemon that can drop stats:
:Arcanine:
Intimidate, Leer
:Toxapex:
Chilling Water
:Arboliva:
Energy Ball, Earth Power
:Bellibolt:
Mud Shot
:Staraptor:
Intimidate, Feather Dance
:tauros-paldea:
Intimidate
:Drifblim:
Shadow Ball
:Umbreon...