Niamh

Origin
Ben's sister, Niamh, first appeared on a Meme Review Stream. She quickly acclimatised to the streaming environment and became a notable/entertaining role on stream. In her debut stream, she made Panta reacting to memes an entertaining stream by offering her unique ability at commentary. Her quick wit and sharpness aided her when she called out Panta live on stream after he broke Twitches TOS. Unfortunately for Niamh, Panta did not take kindly to her being the protagonist. Panta pushed Niamh out of shot to re-establish himself as the dominant character.

Just Chatting Stream.
In a latter IRL stream, Niamh sought to enact revenge on Panta for pushing her out of view by doing the same to him, as seen in this clip.

Niamh has also had her very own Undertale fight meme created for her, which can be viewed here.