Minecraft Dungeons:Clam Launcher

The Clam is a non-alive mob added in the Hidden Depths DLC which acts as the underwater equivalent of the Piston Launchpads seen in the Obsidian Pinnacle, ???, Overgrown Temple, Frosted Fjord, Lost Settlement and the Gale Sanctum, used to launch players up high platforms.

Behavior
When any mob or the player is near, the Clam would shake and if its on top of it, it will launch the mob or player up a height and then close down.

Trivia

 * Clams are seen centrally near the end of the most recent video and are even named in the developer post with the video.
 * In the video, they are referred as Clam Launcher though it is unknown if that is their official name.