While the original ICfB thread was on its first hiatus, Yiqi15 created a fan thread which can now be found here. He created a total of four entries, one of which I helped edit and expand and is hosted onsite: the Fanged Crater Lizard.

For the 10th anniversary of the Speculative Evolution Forum, Dragonthunders created an absolutely enormous artwork depicting the creatures created by the forum's many members. The hashirui, my playful version of Godzilla, was included, alongside two other of my creations not from ICfB.

While I was working on ICfB, I got a ton of suggestions, solicited and not, from various people on what sort of creatures might exist in this world. Of course, not all of these concepts fit with my plans and I couldn't practically adapt such a volume of ideas, but I'd still like to list the ones I can go back and find. Also, be sure to check out my unpublished concepts as well!

Glarnboudin's Concepts:
Giant Gila Monster: Combine it with the gowrow, a monster from Arkansas, to make a big relative to the regular Gila monster.
Killer Shrews: A large predatory hedgehog.
Sharktopus: A Humboldt squid cousin with sharp spines in the place of suction cups.
Fish-man: A giant salamander. People have mistaken them for humanoid creatures before - the kappa of Japan and the infamous 'Homo deluvii' creature are just two examples.
Jaws: A larger, more aggressive subspecies of great white.
Piranhaconda: A large eel.

Beetleboy's Concepts:
King Kong: A giant ape, chalicothere, or giant ground sloth.