Thing type 125, Spring Shell (Yellow), is a turtle-like enemy with a spring on its back. Jumping into a Spring Shell from above will cause the player to be propelled upwards by the spring, potentially allowing them to reach higher-up platforms in the level. Compared to the green Spring Shell, the yellow Spring Shell propels the player higher. Jumping or spinning into a yellow Spring Shell from the side will destroy it. The spring, however, will remain and fall to the floor below. This makes the yellow Spring Shell more suitable than its green counterpart in situations where the spring is necessary for the player's progress through the level. It is unused in SRB2's official levels, though it was previously featured in Techno Hill Zone.
