Scarlet Watermelon Seed

All mobs that are of a level to give you XP (green or better) have a chance to drop this item during the annual Watermelon Event.

You need to collect at least before you can turn them in for a watermelon and at least.

Note that these are NOT Bound so you can use any or all of your alts to farm them, then mail them all to one character to concentrate the haul.