28. Terravore

From far away, it looks like a massive molehill winding through valleys and over ridge lines, a ridge of rocky ground cutting through the trees. Only as you get closer can you make out the incongruous details: the regular height and width of the ridge: the occasional vents oozing steam into the still air, and the gaping cavern where the ridge finally terminates in a glen.

As you get closer, you can see how the land—bushes, trees, rocks, and dirt—looks like it’s been scooped into that maw-like cavern. Then the entire "ridge" shudders and slides forward, and a few more inches of land are shoveled into the maw. The entire ridge is one of the legendary terravores, a kilometers-long biomeld that slowly but inevitably consumes and processes everything in its path.