Today, with the launch of the YO-KAI WATCH: The Movie Event in Theaters, Wibble Wobble has added 4 new Yo-kai you can get, Hovernyan, Buchinyan, Darknyan, and Illuminoct. Hovernyan and Buchinyan in particular have to be obtained on specific days. You can obtain Buchinyan when you login into Wibble Wobble on 10/15, and you can obtain Hovernyan when you login into Wibble Wobble on 10/22.
Darknyan and Illuminoct are obtainable through the Crankakai (as well as Hovernyan and Buchinyan), but Illuminoct in particular is a limited time Yo-kai that lasts from 10/14 – 11/15. In addition, there are limited time missions that involve levelling up Buchinyan, Hovernyan and Darknyan! Do this event while you can, there are lots of things to do in Wibble Wobble right now!