A stupid idea that I had that would be stupid easy to implement is just "Import LANCER mechs as Hazards in Wildsea".

Sure there's no metal in the system, I'd just have to get creative. Some are made of wood and bones of leviathans, some are actual leviathans. Others could be weird creatures that do Weird shit.

A bipedal bark man who operates like a GMS-Everest? Hilarious.

Grand Moss Statue: Everest - 10 Track encounter (high end of Medium difficulty)

A towering, bipedal mass of moss that searches for thunderstorms on the Wildsea
Drive: To carry water it absorbs to dryer areas of the Wildsea.

Sight: - Huge, unevenly sized limbs shamble about, as it leaves a faint trail of wetness where it's massive feet have tred. If it's dry, it is paler in color, and flakes off small parts of it as it moves.
Sound: Soft, wet, irregular footfalls if it's carrying water, raspy, staccato steps if it's dry.
Smell: Strong stench of mildew and damp grass. When dry, a scent of sour wood and fetid water. The smell defies wind, it smells just as strong upwind and down.
Touch: The crezzerin tingles your hand, probing for an opening or open wound. When dry, the moss becomes sharp and jagged like a shattered geode.
Taste:. Wet moss tastes like burning. Not recommended. Thoroughly dried, however, can be used to make a savory broth.

Aspects

Amorphous Mass - The shape of this beast can change as needed, and can break down many types of leaves to add to its mass.
Aggressive//Defensive - When wet, The GMS Everest becomes singularly focused on delivering it's payload, and will use force to deter everyone from it's path. When dry, it looks to avoid conflict, sometimes even shedding parts of itself to block the passage of pursuers.
Herbivore Hunger - Whether wet or dry, the GMS Everest can break down plant matter to add to its mass.
Spring spring sprung - The mass moves with astonishing speed, using its amorphous capabilities to lash out at surprising distance and speed.

You don't have to clear all tracks to defeat it, but clearing a track should significantly impact the encounter, changing it drastically.