|“||Flesh Dwellers!, you have caused pain to my children once too often||„|
|~ Undergrowth as he appears|
He was voiced by Mark Hamill, who also played The Joker in Batman: The Animated Series, the Skeleton King in Super Robot Monkey Team Hyper Force Go!, Maximus in the Fantastic Four animated series, the Hobgoblin in Spider-Man: The Animated Series, Kavaxas in Tales of the Teenage Mutant Ninja Turtles, Stickybeard in Codename: Kids Next Door, Flint in Disney's Buzz Lightyear of Star Command, Niju in Balto II: Wolf Quest by Universal Pictures, Solomon Grundy in the DC Animated Universe, Fire Lord Ozai in Avatar: The Last Airbender, Trickster in The Flash, Dictatious Maximus Galadrigal in Trollhunters, ShiverJack in Disney's Jake and the Never Land Pirates, Agent Goodman in Disney's Recess: School's Out, Popsicles in the 2016 reiteration of The Powerpuff Girls, and Alvin the Treacherous in the How to Train Your Dragon series.
After Vlad Plasmius became Mayor of Amity Park, he started a "beautification campaign" that involved cutting down trees and plants for new buildings, Angered that the people of Amity Park were destroying his children for urbanization, he attacked and used mind vines to turn everyone into his slaves including Danny's Family, Tucker and Sam. With Sam turned into his "daughter", he had her attack Danny, however, with his currently uncontrolled new ice power, manages to escape into the Ghost Zone searching for Frostbite to help him . Sometime later, Danny returned, having finally mastered his ice power thanks to Frostbite. Using it, he managed to destroy Undergrowth's new plant world by freezing his roots causing the giant plant to shrink thus defeating Undergrowth as well a freeing everyone under his control . Undergrowth was reduced to a shrub but was planning to take over again only to be destroyed by Tucker's lawn mower. He was perhaps one of the most powerful ghosts in the series along with Dark Danny and [[Vortex (Danny Phantom)}Vortex]]
He makes a cameo in Boxed- Up Fury in which Walker's goons post a bounty of a $3 million dollar reward for capturing him
He makes on last cameo appearance in the series finale Phantom Planet in which Danny attempts to fight him again but is easily defeated by him and rips his clothes off, moments later he is defeated by the Master's Blasters fighting team.
Later, he along with all the other ghosts in the series with the exceptions of Vlad Plasmius and Dark Danny appear to help Danny turn the earth intangible so the disasteroid can pass through it harmlessly.
Undergrowth regards plants over all life. To him, they are his "children". He sees humans as fragile, temporary lives that won't last long; "Humans are merely a temporary weed in the garden of life...a weed that can be removed." He prefers using humans to do his dirty work.
If he has any weaknesses, the main one would be extreme cold (and presumably fire). Danny's freeze powers weakened Undergrowth completely. His roots & brain are also his main weak spot. Also, when destroyed he will revert into a weed-like state that might take a long time to return to normal. When last seen at the end of "Urban Jungle", he had managed to regenerate into a small, rudimentary form, only to be reduced to mulch by Tucker's lawnmower.
Undergrowth can use mind vines to take control of humans and can grow to enormous sizes. He also does not appear to have the basic ghost powers (aside from intangibility and flight); he is one of the three ghosts that can easily regenerate lost body parts and from being blown or shattered into pieces.
Amorpho | Box Ghost | Bullet | Circus Gothica | Dark Danny | Desiree | Ember McLain | Evil Danny | Evil Syndicate | Freakshow | Fright Knight | Guys in White | Globulous Maximus | Johnny 13 | Kitty | King Gorge | Lunch Lady Ghost | Lydia | Nicolai Technus | Nocturne | Pariah Dark | Penelope Spectra | Prince Aragon | Skulker | The Mawgu | Undergrowth | Valerie Gray | Vlad Plasmius | Vortex | Walker | Youngblood