HORI announced the release of a special DUALSHOCK 4 compatible Dragon Quest Slime Controller for the PS4 users in Japan. This controller will be available from July 29, 2017 with the latest, Dragon Quest XI for 9980 Yen + tax. And yes, as you can see the shape will be a Slime from the game so the comfortable will be a big question.
The dimension of the controller is the following one: 145W x 145D x 124H mm and you can buy it only in Japan. In the gallery you can find the pictures.