In order to unlock Ducken, your monster must be fed cup jellies. At random intervals, after the monster has eaten, a diamond mark may be found on the lid. After five marks have been collected, Colt will mail the marks off to obtain a Quack Doll. When combined with the Strong Glue, it creates a special combination item for creating a Ducken.
For Beaclon to be unlocked, in addition to the method for cocooning, your Worm must be fed 30 cup jellies.
In Monster Rancher DSEdit
Cup Jellies cost 250g per month and slightly decrease your monster's Fatigue.