Even though it is fanmade, I think Wizard, Drive, Build, and Saber having red backgrounds is correct.

Edit: The image is now my avatar

See how well the image is organized. I don’t know what all the Riders will be

I mean, with Daiouika’s colors, if it gets turned into an Auxiliary Vistamp, it would probably be X.

What about this Turtle Vistamp that just appeared? It’s the red-and green one George was looking at near the end of Episode 8. If I remember correctly, Nigo has red and green on him.

V3's main colors are green and red and he was mortally wounded by Turtle Bazooka before receiving emergency surgery to become a Remodified Human.

Which animals will be suitable Vistamps for the Reiwa, Heisei & Showa riders?
Reiwa:

• Revice: Rex
• Saber: Swordfish?
• Zero-One: Giraffe?

Heisei:

• Zi-O: Brachiosaurus
• Build: Stag Beetle?
• Ex-Aid: Jackal
• Ghost: Ankylosaurus or Owl?
• Drive: Velociraptor or Snake?
• Gaim: Mantis
• Wizard: Owl or Salamander?
• Fourze: Gorilla
• OOO: Macaw (Parrot)?
• W/Double: Eagle
• Decade: Megalodon
• Kiva: Crab?
• Den-O: Mammoth
• Kabuto: Bear?
• Hibiki: Bull? Octopus?
• Blade: Cassowary or Rhinoceros?
• Ryuki: Smilodon or Tiger?
• Agito: Moose or Elk/Deer?
• Kuuga: Lion

Showa:

• ZO: ?
• J: ?
• Shin: ?
• ZX: ?
• Super-1: ?
• Skyrider: ?
• Stronger: ?
• Amazon: Mole?
• X: ?
• Riderman: ?
• V3: Turtle?
• Nigo: ?
• Ichigo: Grasshopper

We have 3 new Vistamps based on Showa Riders for Demons to get his Genomix forms.
Amazon-Mole
X-Scorpion
V3-Turtle

Yeah, Demons is definitely our Showa rep.

I feel like Drive Snake would have a Snake curled over its own tail acting as the Shift Tire.

I figured Drives could be specifically the Type: Formula and based on a hammerhead shark.

Also, I hope they use Snake/Cobra as the main form of another Rider to complete the "Ichigo reference trifecta" along with Evil and Demons

I feel like the Cobra Rider is either Sakura or George.

Anyone have thoughts on the remaining Heisei & Showa riders?

The primary 10 Vistamps we have so far are complete. Demons' side with the Showa riders almost with 4.

Ryuki-Condor (The wide face plate reminds me of outspread wings)

Blade-Rhino (because horn, obviously)

Hibiki-Tiger (The helmet design looks like tiger stripes)

Kabuto-Swordfish (Saw some really cool fanart)

OOO-Cheetah (I think the Cheetah Vistamp is for OOO)

Drive-Hammerhead (Specifically Type:Formula. The "head" on the chest is shaped like a hammerhead. I could see cobra, but I'd prefer that be a different rider to complete the Bat-Spider-Cobra reference)

Ghost-Angler Fish (the horn could be the light on the fishes head and fits the glow of Ghosts suit)

Zero-One-Kangaroo (I think the Kangaroo Vistamp is for Zero-One)

That still leaves Agito, Kiva, Wizard and Saber. Not sure what to do with them

But what about the tree? Do any of these animals relate to the tree?

It doesn't need to, the tree doesn't mean anything for the ViStamps

Correct me if I'm wrong but I don't think the Bat is on the tree either, which disproves the idea that an animal theme has to be from the picture