The opening song is a chill and fun electronic song that gets you happy about the show before it even starts.
The Butt Witch's theme, "Party on Saturn" by Seksu Roba. It has a very psychedelic 1970s vibe that reflects her seductive appearance (and possibly her connection with the old sex ed book Reggie threw in the volcano) while the disjointed piano portions reflect her unsettling, sinister nature.
Fans of the short-lived Tuca & Bertie, another Netflix cartoon created by a mostly female staff and dealt with feminine issues, migrated over to this show after the latter's cancelation (ironically, this one didn't last more than one season either).
With Infinity Train, due to both originating as shorts for Cartoon Network as well as the similarities of having a red-headed heroine enter Another Dimension, where the rules of the real world don't apply. However, that's where the similarities end... In fact, the fictional worlds presented are basically polar opposites.
They're also friendly with fans of Amphibia and The Owl House, as all four shows have similar premises (female protagonist goes on adventures in a strange and magical world).
Just Here for Godzilla: Many viewers only watch the show due to The Butt Witch, who is the most popular character since the original short, mainly because of herdesign and voice. Similar to the character of Mr.Towes from My Life Me, there are video edits of the episodes on Youtube to only focus on her.
LGBT Fanbase: Between the many gay side characters on Endless Island (most notably Mack and Beefhouse) and the fact that the main characters crush is a girl, the show gained one in record time.
One of Reggie's embarassing memories reveals that she collected her own scabs in a book. She decides to plant them on the island in the following episode, causing grotesque scab plants to grow.
The main characters puking up worms after arguing with each other, as well as the Butt Witch messily devouring them.
Rooting for the Empire: There's a good number of viewers who root for the Butt Witch, whether it's because they enjoy her character or they find the protagonists obnoxious (or both).
They Changed It, Now It Sucks!: While overall reception to the characters has been positive, there's still a number of fans who dislike Todd and Esther (especially Todd) because they replaced Shane.
What Do You Mean, It's for Kids?: The show has a TV-Y7 rating on Netflix, and yet discusses puberty topics such as wearing bras and menstrual cramps; something many 7-10 year olds would be too young to know much about. However, they are only brought up twice in the entire series.