Mud Walls are naturally-occurring background walls found in the Jungle and occasionally the Underground Jungle. Naturally generated Mud Walls can be destroyed with a hammer, but drop nothing. On the 电脑版和 移动版 they can however be crafted.
If natural Mud Walls are sprayed with Dark Blue Solution they will turn into "natural" Mushroom Walls that likewise don't drop anything when destroyed. If these Mushroom Walls are sprayed with Green Solution they will revert back into Mud Walls or natural Jungle Walls, this seemingly being determined by layer level.
- 电脑版 1.0.6：引入。