While It: Welcome To Derry episode 4 brought the Neibolt House back to the franchise, its importance may not immediately be clear to newcomers unfamiliar with Stephen King’s source novel and its movie adaptations. From It: Welcome To Derry ’s opening scene onward , it was instantly clear that the series wouldn’t be over explaining its lore.
It took until It: Welcome To Derry episode 4 for the series to even start explaining the origins of Pennywise the Clown and, even then, he didn’t appear in the guise that most viewers recognize. Pennywise might be best known as a killer clown, but it was only in episode 5, “29 Neibolt Street,” that this version of the entity returned.
At the end of episode 4, “The Great Swirling Apparatus of Our Planet's Function,” Taniel tells Dick Ha

Screen Rant

SpoilerTV
ESPN
AlterNet
The Conversation
WCBI-TV
Major League Soccer
The Daily Beast
Sarasota Herald-Tribune Sports
She Knows