Yes, Kingler is Viable in OU.

Pokemon Showdown Competitive Singles exists. ADV OU is the best format. This is a good description of the video you are viewing / just viewed. Is this insane? Mightyena and Arcanine are uninvolved Dogs. Jirachi? Involved. Skarmory, Metagross, Salamence, Tyranitar, and more, are members of the metagame at times. #pokemonshowdown #pokemon #pokemonemerald #nvidia