Lilyncookies (or casually, Lily) is a young female artist on DeviantArt, as well as a YouTuber, who draws a lot of pictures of Sonic Fan characters and showcases some of her art on YouTube. Lilyncookies is a good friend of MarioMario54321, who put her in several of his videos since September 2010. She often appears (in the bloopers for example) as a Sonic The Hedgehog Fan named Lily who has a giant cookie addict, hence her full name of "Lilyncookies" (sometimes written as "Lily-N-cookies").
Her only appearance in SuperMarioGlitchy4's videos was in the episode "Ssenmodnar (1,000 Subs)". She has never reappeared since, and it is unknown whether she will reappear in any SMG4 episode ever again.
Lily appears as an orange (humanoid) hedgehog wearing blue clothes. She has two very long quilts, and a fringe partially hiding her right eye (similar to Princess Rosalina from Super Mario Galaxy). She's sometimes mistaken for a cat instead of a hedgehog because of her catlike ears and mouth, and her face, which is often considered cute by many people, with her big blue eyes.
SMG4 used two differents looks of her in the video "Ssenmodnar (1,000 subs)". The first one, used when MarioMario54321 asks Lily if she greeted SMG4, has been made in 2011, while the other one, used when Lily says hi to SMG4, has been made in 2012. That second look was seen in mirror, and then the fringe on the right eye was on the left side instead of the right side. Those two artworks were drawn by Lilyncookies herself, along with most of the other pictures of Lily, and then belong to her.
Unlike several characters who have a different personality in SMG4's videos than anywhere else (Mario for example), Lily seems to have the same personality in SMG4's bloopers than in MarioMario54321's videos: she's delicate and kind.
Appearance in "Ssenmodnar (1,000 subs special)"
Lily appeared in the 41st skit of this episode. In that cutscene, MarioMario54321 asked her if she greeted herself to SMG4. Lily answered him that she didn't know, and told him to let her check. Then she went to see SMG4 to say hi to him, but SMG4 then screamed that she was ugly, and ran away.
It's very probably for that reason that SMG4 never put Lily again in another blooper. It's unknown if she noticed that bad joke in real life, and if she then hates SMG4 now. SMG4 used to say in the description of the video that he would be hiding in a bin if she's angry at him, but he later deleted that for some reason, most probably for Lily and Lily's fans to not see that message due to possible offensiveness.
The way Lily appears in this video was possibly inspired by some of MM54321's bloopers which include her.