Due to being covered in thorns, he may also be based on the prickly seaweed (Acanthophora spicifera), a species of marine red algae covered with many distinctive small spine-like branches in the family Rhodomelaceae.
The fact that he tangles zombies is a reference to how real-life kelp tangles small fish. The tangle in his name refers to how he tangles up zombies and drowns them underwater, defeating them.
Tangle Kelp is unlocked by completing Level 3-3. He can only be planted in water, but will instantly kill any zombie that he abducts, regardless of health.
Tangle Kelp's main advantage in comparison to other ground-based instant plants is the plant's relatively low cost, combined with fast recharge rate and independence from Lily Pad. Because of this, Tangle Kelp can be used as a specialized plant for guarding water lanes early on, acting like an economical, single-target sea mine that buys the player time to set up. Unfortunately, Tangle Kelp's limited effect plus his inability to be planted on land mean that he quickly loses his potential in the mid- to late-level. This means that when considering Tangle Kelp, the player will have to decide between early-game and late-game utility - a Lily Pad plus a Squash or Chomper will prove to be more flexible in most cases.
Tangle Kelp are decently useful against Snorkel Zombies and Dolphin Rider Zombies, as he cannot be dodged by them under any circumstances. In the Fog levels, Tangle Kelp faces competition from Sea-shroom for the role of early pool defense, as the latter is a permanent standing plant and requires no sun to be planted. However, when the Sun production is up, Tangle Kelp can be used as a good instant kill because sun is no longer a problem. He is also effective against the Tall-Nut zombie when it appears on water, as he can instantly defeat that zombie while other plants that can also defeat it instantly on water costs anywhere from 5-6 times higher.
Plants vs. Zombies Wiki has a gallery for Tangle Kelp.
- He, and all other algae (like seaweed and kelp) in general, is technically not a plant, but a member of the protist kingdom, a wastebasket taxon that includes all eukaryotes that do not fit into the animal, plant or fungi kingdoms. This makes it along with Spikerock and the mushrooms the only plant not to be in any members of the plant family.
- The sound that he makes when dragging a zombie into the water is not a new asset and can be recognized in other media. This sound effect originates from the Hanna-Barbera sound effects library which can be heard in some of their cartoons, making it the first plant in the entire series to have sound effects from Hanna-Barbera.
- He, Spikeweed, Spikerock, and Coffee Bean are the only plants that zombies will never attempt to eat.
- In Zombotany 2, he can be shot by a Peashooter/Gatling Pea Zombie and will be defeated.
- He is one of the twelve plants that appear in the seed selection screen after the player gets the Grave Buster in the online version with the others being Ice-shroom, Lily Pad, Potato Mine, Threepeater, Doom-shroom, Jalapeno, Spikeweed, Torchwood, Tall-nut, Cactus, and Blover.
- He looks similar and has a similar name to Tangela, a Generation I Pokémon.
- He is nicknamed "水草兄" ("Kelp Bro") in Plants vs. Zombies: Journey to the West.