The Carolina Reaper, originally named the HP22B, is a cultivar of the Capsicum chinense plant. The pepper is red and gnarled, with a small pointed tail. In 2013, Guinness World Records declared it the hottest chili pepper in the world, surpassing the previous record holder, the Trinidad Moruga Scorpion". Other varieties have been claimed to be spicier, but are not confirmed by Guinness. 

The sensory heat or pungency detected when consuming a Carolina Reaper derives from the density of capsaicinoids, particularly capsaicin, which relates directly to intensity of chili pepper heat and Scoville scale.[3] Bred in a Rock Hill, South Carolina greenhouse by "Smokin" Ed Currie, proprietor of the PuckerButt Pepper Company in Fort Mill, the Carolina Reaper was certified as the world's hottest chili pepper by the Guinness World Records on 11 August 2017. The official Guinness World Record heat level was 1,641,183 Scoville Heat Units (SHU) in 2017, according to tests conducted by Winthrop University in South Carolina. The figure is an average for the tested batch; the hottest individual pepper was measured at 2.2 million SHU.

The crossbreed is between a "really nastily hot" La Soufriere pepper from the Caribbean island of St. Vincent and a Naga pepper from Pakistan, and is named 'Reaper' due to the shape of its tail. It has been described as having a fruity taste, with the initial bite being sweet and then immediately turning to "molten lava".

In May 2017, Mike Smith of St Asaph working with Nottingham Trent University claimed to have surpassed the Carolina Reaper with his Dragon's Breath pepper, reported to be 2.4 million SHUs, and applied to Guinness World Records for confirmation.

In 2017, the creator of the Carolina Reaper claimed to have bred a stronger pepper of 3.18 million SHUs. The pepper, known as Pepper X until its final trade name is chosen, was not confirmed by Guinness.

For growing, the pepper has been described as "a good all-rounder to try at home" by UK ethnobotanist James Wong, who said that they require temperatures of at least 18–20 °C (64–68 °F) and suggested growing in 30–40 cm (12–16 in) pots to restrict growth and produce fruit sooner. When fully ripe, two peppers occupy the palm of the hand.

SOWING ADVICES: Capsicum chinense chilies germinate and grow best when soil temperatures are above 29/30°C. In most regions of the country, peppers should be started indoors and then transplanted outdoors as the weather warms. Sow peppers indoors 6-8 weeks before transplanting. Plant seeds at a depth of ¼ inch and make sure the soil remains warm throughout the germination period.