Bill is a Nostalgia Critic character with a rich and well defined backstory (that we never get to see). Nostalgia Critic claims in Norm of the North that Bill 'takes care of [him]' and if Bill weren't there, he would starve to death, and also that Bill had been the King of Iceland. He's well known and loved by other characters (who insist that he has always been there), despite the fact that the Smurfs 2 review was his first appearance.
His catchphrase is 'MmmmHmm!', which may very well be the only thing he can say, albeit in different inflections. In his first appearance, he commits an act of betrayal by spoiling the next week's sequel review, which the other characters note goes completely against his established character. He responds to this accusation with his signature catchphrase, but not before dealing with Tamara's woes relating to family disputes, an act which Nostalgia Critic describes as being 'so Bill'.
He later makes a cameo in the Garfield 2 review, where the Critic challenges the audience to name 'one good thing' that came out of Sequel Month. Bill appears to once again state his trademark catchphrase, but Critic insists that he was always there. Bill next appears as a psychiatrist for Devil Boner and Hyper Fangirl in Old vs. New: Evil Dead, where it is revealed Bill is Benny's brother. Bill also makes an appearance at the end of the Suicide Squad review as a replacement for The Joker in the final scene.
In the Norm of the North review, the Critic asks him to comment on a scene in the movie, but Bill is nowhere to be found. This causes him incredible distress and sends him into a brief panic, but Bill arrives not long after, back from what was apparently a reign as 'temporary King' of Iceland. He and Critic then decide to perform a bizarre dance number aptly titled 'The Bill Dance'.
In the review of The Sorcerer's Apprentice, Bill appears to prank call the Critic, tricking him into thinking he's with a recently brought-back-to-life Stanley Kubrick, who wants to make a movie with the Critic on the moon.
He was initially supposed to play the kid Bill in the review of It (2017), but for the sake of dialogue, he was replaced by New White Bill.
- Bill's sudden appearance, as well as everyone around him pretending that he was always there, parodied The Smurfs 2 randomly introducing new characters without explanation as to who they are.
- Bill's spoiling of the next review in The Smurfs 2 Review came as a surprise, because Bill has clearly been presented as nice apart from that scene.
- The only thing Bill ever says "Mmm..hmm" (instead of "I am Groot"). Despite this, Bill has a wide range of vocabulary, from casual "hmmm" to an eloquent monologue of "mmmmmhmmmm!".
- He's the second character played by Malcolm Ray to be named Bill. The first was the editor during the Labyrinth review.
- He is revealed to be Benny's brother in Old Vs. New: Evil Dead
- In Norm of the North, Nostalgia Critic claims that if Bill isn't around, no one will 'take care of him' and he will 'starve to death'.
- Bill was stated to have been the 'temporary king of Iceland'.
- His replacement in It (2017) "for the sake of dialogue" seems to indicate that the Critic is aware that only he, Tamara, and the rest of the Channel Awesome team can understand what Bill is saying.