The first two photos illustrate Earthen plants that have developed a taste for meat. If these plants look like gruesome monsters, one can only imagine the development of alien plants on other planets in the galaxy that have evolved according to a different genome set, unlike life on Earth.
The plants evolved when photosynthesis no longer became a prime factor in the life cycle of plants evolving on a planet with less sunlight. The plants would most likely develop another way to survive, by capturing and eating small animals, like mice and other rodent-like creatures.
The Day of the Triffids is one example, a 1951 post-apocalyptic novel by the English science fiction author John Wyndham.
After most people in the world are blinded by an apparent meteor shower, an aggressive species of plant starts killing people.
The protagonist is Bill Masen, a biologist who has made his living working with triffids—tall, venomous, carnivorous plants capable of locomotion.
It's not too difficult to imagine a massive plant living within a gravity environment several times of Earth, with strong leaves and ensnaring teeth, much like the Earth's Venus Fly Trap plant that rapidly catches and devours insects for their meat.
