在地球上的南美洲亞馬遜河流域，居住著一個民族舒爾族，他們一直和外界都沒有聯繫和溝通，顯得神秘而令人神往，他們崇拜的圖騰是巨蟒蛇。美國的科學家們對舒爾族有著濃厚的興趣，他們組團前往去探究。人類學家史蒂文·凱和紀錄片導演泰莉·勞瑞帶著其他的團隊跟從一個名叫保羅·沙龍的嚮導邁入了亞馬遜熱帶雨林，他們的隊伍中混雜著偷獵者，妄圖將巨蟒蛇抓住，賣到美國去大賺一筆，由於貪心和狂妄，他們從此陷入危機，多數被巨蟒蛇殺害。
歐洲的科學家一直對蟒蛇有著濃厚的興趣，他們鑽研蟒蛇已經很長一段時間了，雖然科學家的動機是為了科學實驗，但是他們背後的投資商和贊助商卻並不這樣認為，他們想把蟒蛇當做搖錢樹，獵取巨大的經濟效益。一日，贊助商在觀察科學家研究蟒蛇的時候，不小心把兩條蟒蛇釋放了，蟒蛇順利的逃出了實驗室，流竄到大森林裡，由於距離城市比較近，蟒蛇有可能會跑到城市去，那樣會造成巨大的損失和人員傷亡，而商人則會被行政調查和判罪入獄，為了避免這種情況的出現，贊助商不得已請來了勇敢的抓蛇獵人，而抓蛇獵人和蟒蛇則會上演一場生死之戰。
科學家抓到了蟒蛇生的小蟒蛇，並且製作出了一種血清，可以使得人和蛇的壽命延長，同時可以治療疾病。大亨默多克先生得了骨癌，得知血清可以治療癌症，於是派手下去尋找血清和殺死科學家。當默多克的手下到來時，蟒蛇已經喝了血清，變成巨大的蟒蛇，並且殺死了科學家，流竄在森林裡。此時，考古學家也在森林裡搞科研調查，因為車子出事在森林裡步行，他們發現森林裡到處是死人，感到驚慌和害怕，決定離開森林回到城市去。當考古學家返回時，遇到了科學家阿曼達，阿曼達是默多克先生追殺的科學家，她成功地逃過了默多克的追殺，並且巧妙地利用蟒蛇殺死了默多克的兇手，為了維持生態平衡和防止蟒蛇流竄到城市裡去殺人，阿曼達隨後搜索和斬殺了蟒蛇。
故事讲述了秦宇的未婚妻在调查卡斯集团时离奇死亡，为了在法庭上成功指证这个作恶多端的生物集团，秦宇跟踪掌握集团犯罪证据的杰森上了邮轮，却突遭变异蛇群攻击，误入卡斯集团进行非法实验的岛屿，岛屿奇怪的生态环境与巨蛇的再次来袭，令秦宇等人身陷绝命危机，而后众人齐心协力相互配合脱离险境，并圆满将卡斯集团罪行公布于众的故事
A hybrid creature - half piranha and half anaconda -- attacks a low-budget horror movie crew on location near her nest when her egg is stolen. Now they must outrun and kill the deadly piranhaconda as well as stop the mad scientist who stole the egg - before they all become dinner.
A set of vipers has been taken by scientists to mutate them to make a cure for cancer. As their experiment goes awry, the vipers escape into the woods - they're not only biting people, they're actually killing people, in a little town.
In an old house, a man is bitten to death by a snake. The special services and the media congregate but are only able to find a few snakes. Later, a group of cobras invade the building which threatens the lives of the habitants.
During the construction of luxury apartment buildings a huge nest of thousands of snakes is discovered. Francis Chang (the boss) refuses to delay the construction and orders to kill all the animals. He is repeated warned by his wife, who had some nightmares concerning him and the snakes. They do not manage to kill all snakes and so they take revenge on the construction workers and Francis Chang. Soon thousands of killer snakes under the lead of a giant Boa invades the building an kill all the new inhabitants. Even a snake master can't stop them.
An American submarine leaves Tierra Del Fuego, and one of its crew has secretly brought aboard a container full of poisonous snakes which escape storage and bite key personnel on the submarine, causing an accident that cripples the vehicle so that it drops to the bottom of the Southern Ocean. Worse still, the snakes are still at large on the submarine and complicate the efforts of the crew to escape the sunken vessel.
A gigantic serpent is captured on a remote island and shipped to an American college for experimentation.
The King of the Snake Monsters is attempting to revert back to human form but is opposed by the womanizing owner of a popular restaurant that specializes in medicinal snake soup.
A woman transforms into a snake-headed killer.
Police investigate a strange series of snakebite deaths.
A married man falls in love with a beautiful tour guide but is unaware of her symbiotic relationship with a deadly cobra that has killed all of her previous suitors. This was remade at least two other times.