u/Perfect_Tension_546

The first appears to be a Chomper variant similar to the Zen Cactus, though its intended function is unknown; it likely would have operated in a similar way to the Zen Cactus.

The second is a rainbow Chomper; like the previous one, its intended function is unknown.

I came across this while browsing Facebook.

I've always wondered in my mind if Krystalak and Obsidius were in the Monsterverse

These two images are the only pieces of concept art for him; his first two designs were of a giant mammoth, but they were discarded.

https://x.com/Euphoric_Bros/status/2083255091323088972

https://x.com/mascotmassacre/status/2082120370497429968

https://x.com/Euphoric_Bros/status/2077469379059503375/photo/1

You can find more concept art by Orga at this link: https://wikizilla.org/wiki/Orga/Gallery

This is the only remaining concept art from Rodan's Showa era

P.S.: I didn't include Vagineer because the design of its mouth is based on something you probably already know, and that's why I didn't want to include it.

https://x.com/PillarChase_2/status/2069205336288833928

https://x.com/PillarChase_2/status/2068842610181964184