The Riffkin girl first appears as a small, blonde girl in a torn, white dress. She is somewhat dirty, due to living under poor sanitary conditions.
She is also alarmingly thin and seems weak and frail at first. Until Ebola, the protagonist of the show, frees her. She then proceeds to change to her true form. Her eyes turn black, she sports jagged teeth and, in the end, a number of insect or spider-like legs emerge from beneath her dress, replacing her human feet. Her smile grows wider than a regular human face would allow.
The little girl is first seen by Ebola, who looks through the window of her room and sees her through another window across the street. They wave hands at each other.
Later, Ebola sees her threatened by a silhouette she (correctly) assumes to be her father. After failing to alarm her parents, who don't believe Ebola's story, Ebola is sent over to the Riffkin-House to get to know her neighbors, bearing a ginger bread man. However, on her way over, she meets a boy who tells her scary stories about the family Riffkin: According to him, the girl had four sisters, who, "... fell down the stairs." The boy implies the falling down the stairs story to be some sort of cover up.
After entering the house, Ebola overhears the girls parents, planning to get rid of their daughter, whom she then finds shackled in her room, surrounded by torn toys and anything-but-fresh leftovers. Ebola frees the girl before her parents can enter the room to stop her. The girl assumes her true form and brutally kills her parents. While Ebola is suffering a mental breakdown, she exits the house, changing back to her human appearance. On the street, she turns to the window and waves at Ebola in her first appearance while eating the ginger bread man.
Ebola, who had recently been released from the Asylum after being treated for her mental illness (presumed to be some form of psychosis), is advised by her reflection not to tell the family what she just saw, as she would be sent back. Ebola asks if what she saw was real, to which her reflection states that it is uncertain, and Ebola has no way of knowing.
Connection to Slender Man Edit
The most obvious connections to the Slender Man Mythos are the girls limbs, which she displays in her true form, but also her association to children. She uses a friendly appearance to lure them into her reach, like she did with Ebola. However, she didn't harm her, just used her to get free. That said, it's very likely she killed (and ate) her sisters.
She also displays supernatural abilities, as she is seen to erase candles after getting close to them.
Another interesting thing to note is the scene in which she mutilates her parents with childish glee: During a number of disturbing pictures, a symbol is shown a few times. This symbol is, in the mythos, known as the Operator Symbol and often linked to the Slender Man.