Triffids are fictional plants featured in the science fiction novel "The Day of the Triffids" by John Wyndham. They are characterized by their tall, mobile stems and venomous stingers, which they use to attack humans. Triffids are known for their ability to move and their aggressive behavior, making them a significant threat in the story. In the novel, a global catastrophe leaves most of humanity blind, allowing the Triffids to thrive and become dominant. The story explores themes of survival and the consequences of human actions on nature, highlighting the dangers of unchecked scientific experimentation and environmental neglect.