Benny was a boy that wanted to trade his Wobbuffet for a different Pokémon. While he offered many people his Wobbuffet, many refused. When he was about to trade Wobbuffet at the machine, Jessie came (dressed in a lab coat) after blasted off by Tauros and accidentally switched her Lickitung for his Wobbuffet. Benny was glad he traded Wobbuffet, but wished Wobbuffet good luck with his new master.
Benny's new Lickitung used to belong to Jessie until she accidentally traded it for Benny's Wobbuffet.
Nobody wanted to have Wobbuffet until Jessie was knocked into the machine and the Poke Ball containing her Lickitung was dropped into the machine and traded for it. It follows Jessie until she went to Unova.