A Ding Dong Dell gatekeeper has had his precious Cat's Whiskers stolen by a monster.
This errand is available to complete after defeating Porco Loco in Hamelin, after defeating Shadar.
In Ding Dong Dell, talk to the guard on the right at the entrance to find out that he lost his Cat's Whiskers, so we need to get them back for him. Go out onto the World Map, then make your way to the area that you had to make a bridge for to the west of The Deep Dark Wood. At the southern part of this area (directly southwest of The Deep Dark Wood) is a large yellow creature. Encounter and beat this Igneous Supremous to obtain the cat's whiskers. (Using Water attacks will drop it quickly.) Afterward, return it to the guard to complete the errand.