Swaggasaurus Rex

Hey guys today I have the most exciting news ever. So when I was hunting for Pokemon in the grass meadows in Mitsol today, guess what I found?! A Swaggasaurus Rex, it was amazing. He is not a pokemon because when I tried to catch him with my Pokeball it just broke. So I need YOUR help. If you know anyway how to catch a Swaggasaurs Rex comment below because right now I am camping out in Mistol figuring out how to catch such a diligent creature. THANKS and as ALWAYS have a great day Pokehunting!!!!