Epic Noggin has Entbrat and Fwog, Riff and Drumpler and Cybop and Quarrister, and Shellbeat and Shrubb

As for Furcorn, its Mammot and Furcorn on plant. Edit: A Furcorn and Twiddle combination has been reported on Cold Island.

Update: I have bred an Epic Noggin on Plant island. It took around 30 attempts BUT every time I bred it the Fwog was the monster selected on the right. For some reason I swapped it and bred Entbrat on the right and Fwog on the left and got it first try. This may affect the chances or even be required to successfully breed it.

Update: I haven't bred any more Epic Noggins (Using the same breeding combination) so I believe it was just luck.