As befits of a monster appearing on the final dungeon, the Primal Coco is also the ultimate Bird-type monster: its stats are all through the roof, it's fast and also has access to the moveset of the Bird Knight, which is the most complete among all of its predecessors. Therefore, it will be difficult to defeat one of these things if the player's party isn't well equipped or doesn't has access to strong Song Magic such as the ones found in the final Cosmosphere levels of the three Reyvateils. As always, paying attention is necessary for blocking its multi-hit attacks, while it would be a good idea to use items to support the damage done by the party members until the Reyvateils have evolved and charged their songs enough to destroy these birds.