Cleveland Browns star David Njoku burned nearly a quarter of his body during his serious bonfire mishap earlier this season ... with the tight end's doctor revealing his injuries were "probably the most painful burn you can have."
The 27-year-old sat in front of a camera and detailed the September 29 incident this week ... giving a play-by-play of exactly what happened that fateful night.
Njoku said he likes to have bonfires in his backyard to relax on Fridays ... and after running out of his usual lighter fluid, he tried out a spray to ignite the logs in his pit.