You should be able to catch it with just about anything if you low it's HP to 1 with False Swipe and put it to sleep, but if you want to catch something with a low catch rate, your best bet is almost always going to be Timer Balls. Try a Quick Ball on the first turn, as that gives you a catch rate of x5, but if that doesn't work, lower its HP, give it a status, and use Timer Balls.