okay so, so far I have successfully gained four of the turtle forms (here), and have also seen this one

I haven't seen the last one yet. or maybe I missed it or forgot it? does anyone know the last one

i've seen it! can't recall where unfortunately, but it's probably metal aligned - instead of spikes on the back, the shell was flat with ridges on the edges (had to look this up but it looked similar to a step cut gemstone!) and silvery

edit: okay i just scrolled through 'all pets' briefly and eepy has one!

@wit
thank you!!