Glass brother

Glass Brother is the brother of Salad Fingers and the son of Glass Mother, who favors him over the former. He appears in episode 11 that was not his first appearance though he actully appeared first in ep 5 picnic as hes responding to salad untill in 11 he gets cursed by his mother

Glass Brother is Salad Fingers' twin, physically looking identical to him and wears the exact same clothing as him. His teeth turn to nails and his body ripples in a fashion similar to a reflection being disturbed when Salad Fingers rescues Hubert from the Glass World. Glass Brother is Salad Fingers' reflection who lives within the Glass World with his mother. Unlike the real Salad Fingers, Glass Brother is unpleasant and cruel, which Salad Fingers attributes to him being "raised under the beast's sun". Glass Brother functions as a warden of sorts, prohibiting Salad Fingers from leaving the abuse and deliberately makes it worse for him by preventing him from giving the Glass Mother her bowl of food and then mockingly rasping at Salad Fingers.

Eventually, Glass Brother discovers Hubert Cumberdale (The Real Boy) who had been recently given skin by Salad Fingers. Glass Brother then steals Hubert Cumberdale and takes him into the Glass World. Upon acquiring Hubert Cumberdale, Glass Brother traps him in a jar in his room. With him gone, Salad Fingers infiltrates the Glass World to retrieve Hubert Cumberdale. When Hubert was within arm's reach, Glass Brother awakens and alerts their mother about Salad Fingers' plan. Salad Fingers manages to escape the Glass World with Hubert Cumberdale through a puddle, and when Glass Brother tries to emerge from the puddle, Salad Fingers pushes his fingers back into it.

Trivia
.Glass Brother and his family are representative of schizophrenia. Their behavior directly reflects that of auditory hallucinations, which in real life can be disturbing, violent, and self-abusive in nature. .Like a real sibling, he gives Salad Fingers a hard time and often antagonizes him.