Citron

Clemont is the Gym Leader of Lumiose City and, with his sister Bonnie, meets Ash when the gym mechanisms malfunction and almost kill Ash. He seems very caring toward his sister. He is known for making numerous inventions, including the Aipom Arm on his back. He joins Ash after the Lumiose Gym at Prism Tower gets damaged, but Ash doesn't know his true vocation until they return to Lumiose City. He has left the gym under the control of a robot he created, but has promised to battle Ash himself when he has four badges.

(Source: serebii.net)

Current Pokemon in his team:
Diggersby
Dedenne
Chespin
Luxray