I think Kameba has changed the most since "Yog, Monster from Space" to "GMMG: Tokyo S.O.S". Kameba has changed the most because in "Yog, Monster from Space", he looked kinda like a baby Kaiju with the big eyes but in "GMMG: Tokyo S.O.S", he looks a lot more aggresive and hid shell looks larger wich, is a good point for me. He looks a lot more like a snapping turtle now.

Before: After:

I think the most improved monster is Baragon. He used to look like a phony-looking dog in Destroy All Monsters and Frankenstein Conquers The Earth. But, in GMK, he looked EXTREMELY ferocious in his few scenes. His eyes, ears, and horns looked much better than from the 60s.

I think that Mothra looks a lot better in GMK than she did in Godzilla and Mothra: The Battle For Earth. The weirdest thing about her, though, is that instead of looking like a massive moth, she greatly resembled a huge wasp of some type. A little strange, but none the less cool! And she had an awesome stinger attack that seemed to do a lot of damage to Godzilla in GMK. So, that's why I think Mothra is the most improved kaiju of all.