Looks like Mattel finally found a way to bring these figures to the masses!
These two-- along with Mer-Man, Moss Man and Scareglow-- were shown at Comic-Con a few years back as a fun project that the [MOTU sculptors] the Four Horsemen created on their own. Mattel made it clear at the time that there were no official plans to do anything with the figures other than share them with fans, but if there was enough interest, that they'd try to find a way to release them for purchase.
We may never see the other figures from this unofficial line, but getting the two "big guns" is definitely a nice and unexpected surprise.
Again, as with all the Mattel exclusives for SDCC, you can pre-order this for pick up at Comic-Con on the MattyCollector.com site.