The few character descriptions of Tangle Kelp describe him as a difficult and foolish, albeit well educated individual with a particular fondness for philosophy and deception.
As of Plants vs. Zombies 3, he has appeared in three main-line games.
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.
- Main article: Tangle Kelp (PvZ)
Tangle Kelp costs 25 sun to plant and ensnares the first zombies he encounters and drags it to the bottom to the water, instantly defeating it. This makes Tangle Kelp the aquatic equivalent to both Potato Mine and Squash, having the former's low sun cost but lacks an arming time and can attack from behind like the latter.
Tangle Kelp is exceptional in that he costs one third of what would require to plant Squash in the water and is able to be planted in water all on his own unlike Potato Mine, who cannot be planted on water even on a Lily Pad. Unlike Potato Mine and Squash however, Tangle Kelp can only defeat one zombie at a time and cannot be planted on land.
- Main article: Tangle Kelp (PvZ2)
Tangle Kelp returns in the sequel Plants vs. Zombies 2 as the second plant unlocked in the Big Wave Beach world, where he receives more utility.
He retains his cost and function as an aquatic single-use, instant-kill plant, but attacks much more slowly than how he does in the first game. Whenever Tangle Kelp attacks a zombie too large to be dragged underwater such as a Gargantuar, he merely deals 400 damage to it instead.
Much like Lily Pad, Tangle Kelp offers more functionality in Big Wave Beach, due to there being a larger amount of water on the board as opposed to in the Pool area in the first game. Tangle Kelp can also be levelled up to allow him to attack more than one zombie at a time.
- Main article: Tangle Kelp (PvZ3)
Tangle Kelp's most recent appearance is in Plants vs. Zombies 3, where he returns as a plant usable in Lost Keys Lake's water areas.
Tangle Kelp in this game costs only 1 sun to plant due to the updated sun counter, and his attack works rather differently than in previous games. Rather than dragging zombies underwater like he's done in the past, Tangle Kelp now instead lunges at zombies that approaches him and deal a large amount of damage that defeats the target instantly regardless of armor.
Tangle Kelp faces unique challenges in this game due to Lost Keys Lake's water lanes varying in layout from level to level, which leave him in completely situational positions in certain lanes and completely unavailable in others. Another challenge Tangle Kelp faces in this game is the Water Surge mechanic that can shift the positions of plants planted in water meaning that, if the water flows vertically, Tangle Kelp could be moved to an entirely different lane than the one he was meant to be in, allowing particularly tougher enemies to continue advancing down the lane possibly unopposed.
Plants vs. Zombies Wiki has a gallery for Tangle Kelp.
- While not officially confirmed to be the same plant, Spiky Spikeweed from both Garden Warfare games bares a strong resemblance to 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 plants in the original game not to be in any members of the plant family.
- Tangle Kelp was originally planned to appear in the Chinese turn-based RPG game Plants vs. Zombies: All Stars. His active ability would have been to target the closest zombie, while damaging all zombies nearby. It is currently unknown why his appearance was scrapped.