It's a little out of character as Vigor prevents critters from dying due to damage and the Fog Crawler definitely could die when fed enough bullets, but it's at least got the same butt-clenching vibe as the Fallout Fog Crawler
So it stands to reason that Enchanted Rare cards are the most highly sought after cards in any given set, especially as cards at this level of rarity are found at the rate of roughly 1 in every 72 booster packs (which is 1 in 3 booster boxes!)
Ajani, Outland Chaperone can spawn kithkin tokens, and if you build up to the -8 you get to drop a bunch of small-ish permanents on the battlefield
It is still a creature spell, of that name, with the CMC of the original card (not the mutate cost)
It isnt much to go on, but if you see someone with, say, a large amount of Unglued Plains, Mountains, Swamps, and Islands for trade but no Forests, alarm bells should ring in your brain