Tail Whip is your friend.
I was able to do two of the three with my Ony Whelp. Tail Whip, TW, Heal, ect.
I pulled my third next because I had gotten to the Elemental. Frog Kiss, Water Jet, FK, Heal, repeat til dead.
My second was mostly a back up I did need but he finished it off and that was that!