Spotted Worm Sea Cucumber – Synapta maculata – Sometimes growing as long as 10 ft, it is one of the longest sea cucumbers in the world. The 15 tentacles of Synapta maculata surround the mouth and are used in surface feeding. They are about 1 in long when extended and have a short stem and a feather-like blade with thirty to forty pairs of pinnules (secondary branches). The outer surfaces of the tentacles have numerous bulges and are adhesive while the inner surfaces are smooth, with clusters of cilia on the proximal parts. The tentacles are in continuous motion; they flatten themselves against the substrate or seagrass leaf blades and collect food particles by adhesion, then bend inwards until the tips are in the mouth, where the food is scraped off by the buccal (mouth) sphincter muscle. The whole process takes only a few seconds, and several tentacles can deliver their loads at the same time. You can watch them go at https://www.youtube.com/watch?v=7ru1fcsFp1M

Now for the comparison to The Cookie Monster: https://www.youtube.com/watch?v=OqL7jyrXhLs

Etymology:
Synapta: Latin ‘joined together’
maculata: Latin maculosus ‘spotted’