Audrey II

"Audrey II" is the Earthen nickname given to a species of mobile, carnivorous, sapient flora. While still sprouts, they already have the natural, perhaps instinctual intellect to trick other sapient species into feeding them to adulthood. They can almost instantly learn the language of native lifeforms, promising their caretakers fame and fortune if they feed them fresh meat and blood. As they mature, their pod becomes impervious to conventional attacks, although their vines are still susceptible, albeit difficult to hit. They are capable of hypnotizing potential prey items into feeding themselves to the flora. Once one of them grows large enough off an ample supply of blood, it will sprout flower buds in order to spread the infestation further.

This species appears to have some method, perhaps biological, of space travel, as well as the capability to completely overrun planets. Presumably afterwards it uses the planet as a launch pad. They have attempted invasion of the Earth at least once.

History
An Audrey II seed landed on Earth in the 1960s, where it was found and sold to an American flower shop employee, Seymour Krelborn, and named after a colleague with whom he had feelings for. Struggling to prevent the plant from wilting, Seymour accidentally pricked his finger and realised it fed on blood. Audrey II's exotic and enigmatic background results in Seymour becoming a local celebrity, all the while it rapidly increased in size and appetite.

Eventually, Audrey II gained the ability to speak (and sing) and encouraged Seymour to feed it Human bodies, promising that his fame and fortunes would only grow with it. Seymour initially intends to kill Audrey's abusive boyfriend Orin to feed the plant but is unable to go through with it, only for Orin to die anyway from abuse of nitrous oxide. Seymour dismembered his body and fed it to Audrey II, fuelling its growth even further. Later, Seymour is confronted by his employer, Mr. Mushnik, who believed Seymour to have murdered Orin and attempted blackmail him to take ownership of the plant. Although Seymour initially complied, Audrey II proceeded to devour Mushnik whole.

Despite his growing success, Seymour becomes concerned about Audrey II's continuous growth and the possibility of it spreading beyond the flower shop. When Audrey II learnt of his intention to leave and let it starve, it impersonated him over the telephone to lure Audrey to the shop. Before the plant could devour its namesake, Seymour intervened and decided he had to kill it before it could spread more of its kind across Earth. In the ensuing confrontation, Audrey II revealed its extra-terrestrial origin (describing itself in song as a "mean green mother from outer space"), as well as its intention to spread more of its kind across the planet and devour all life on Earth. Audrey II proceeds to destroy the shop, but is killed by Seymour using an exposed electrical cable. Despite the destruction of the original plant, a single budding of its species was seen in Seymour and Audrey's suburban garden later, leaving its continued status on Earth unknown.

In an alternate ending to the movie, Audrey II overpowers Seymour and devours him, leaving only his shattered glasses. Audrey II buds are found across the United States and sold in stores, where they sell in the millions. Each one convinces their owner to feed them blood, fueling their growth, and eventually the Earth is overrun by the plants. The fully-grown Audrey-IIs are shown having the strength to topple buildings, fling cars, knock over street lamps, and warp bridges. One is able to demolish a factory by blowing into a smokestack, and the plants are shown to be impervious to shots from M1 Garand and M14 rifles. A lone Audrey-II stands victorious over the human race atop the Statue of Liberty after conquering another planet.