Bobbin was the male tribute from District 8 reaped for the 10th Hunger Games. His mentor was Juno Phipps. During his interview with Phipps, he impressed her by mentioning he knew five different ways to kill someone with a sewing needle. He died very late on Day 1 and finished in 13th place of the 24 tributes. He was preceeded in death by Dill, the female tribute from District 11, and followed in death by Sol, the female tribute from District 5. Bobbin is the first person future President Coriolanus Snow has killed directly.
During the Games, Sejanus Plinth snuck into the arena to perform a traditional District 2 death ceremony on his assigned male tribute, and former District 2 childhood community neighbor, Marcus' dead body and then die in protest of the Games. Coriolanus Snow was sent into the arena to successfully coax Sejanus out, but as they exited Bobbin attacked them unsuspected with a knife. In defense, Coriolanus seized a board and beat Bobbin so badly that the surrounding area was covered in blood, dislodged one of the boy's eyes, and rendered his face so swollen and bruised it was unrecognizable. All of which lead to Bobbin's eventual death.
Although guilt was Snow's immediate feeling after killing Bobbin, it changed after Tigris' horrified reaction of him being in the arena and commentary "Poor Lucy Gray." For the first time he felt glad in the realization he killed Bobbin and the effect it will have. It was in Bobbin's death, Snow started to fully accept and understand the lessons being taught by Dr Gaul, involving the perceived reasoning, reality, and need for the Hunger Games along with the conclusion that humanity is defined by who has, how to keep, garner support, the enforcement, and survival of control. Through Bobbin's attack on Plinth and Snow, even after recognizing the two as the only mentors to publicly show empathy to the well being of the tributes, plus there was nothing to gain by their deaths since they were not in direct competition with him, that Snow truly grasps the depth of the districts' hate of him and all the Capitol.
He also discovers by his own reaction to Bobbin's attack, what Dr. Gaul means by her opinion on human's inherent animalistic reaction, no matter who you are, where you live, or how much money you have, that one's response to real and perceived threats will always be violence not peace. Here Bobbin's death furthered Snow's realization that to protect his and the Capitol's earned entitlement, power, and control, as well as save the districts from themselves, the war will never be over. But by limiting hope and creating realistic expectations, it can be contained indefinitely.
Since the events leading up to and following Bobbin's demise all transposed at night after all the mentors and attendants had left for the night and Lucky Flickerman's play-by-play recessed, the view inside the arena was limited and any movement hard to decipher without explanation. The arena itself contained little to no light other than the natural moonlight and the Capitol's view was only a single wide angle lens. Darkening an already dimmed stream could be explained away by clouds, so this eased the Gamemaker's job of damage control and Bobbin's death was easily covered up. Luckily, Lucky and the mentors were initially more confused on how Marcus' body was moved and less on Bobbin's grotesque body and death, other than his mentor Phipps. No explanation was given and his memoriam quickly glossed over to instead celebrate the Games were officially half-way to crowing their winner, over Phipps objections and demands for answers. Phipps remained skeptical, however, still covered in celebration confetti, found a seat in the newly eliminated mentor's viewing section. Bobbin's body was eventually moved by Reaper, along with the other dead tributes and covered, in part, by a Panem flag until after the Games had it's Victor and then removed for the arena's cleaning and repair with the other 13 dead tributes who lived long enough to start the Games to die inside.
A bobbin is a type of spool used to hold thread or yarn.