Before I die, I will own a complete set of these guys. This is a commercial from 1978 which features Mattel’s 24″ Mazinga and Gaiking along with Godzilla. In addition to those three, the US saw figures for Dragun, Daimos, and Raideen as well.
These large figures were scrutinized for their flying missiles and small parts that could poke out eyes and maim small children. As a result, the line faded away in 1980. You can find these on eBay for around $75-100, but if they have all the parts and original box, expect to pay upwards of $250 each.
If anybody has any of these collecting dust and looking for a good home, I have a shelf just waiting for them!