Pennywise The Clown refers to a series of images that use shots from the 1990 made-for-TV mini-series adaptation of Stephen King's It. Online, people use the image as a reaction or to portray the things that would entice them in the face of certain death.
Pennywise first appeared in the 1985 novel It by Stephen King. In the book, Pennywise is an ancient demonic entity acts who returns every 27 years or so to feed on the fears of children. The character, generally, returns to the town of Derry, Maine, when an act of extreme violence, resulting in the death of numerous people, just occurred.
On November 18th and 20th, 1990, ABC aired parts one and two, respectively, of a live-action adaptation of It. In the film, actor Tim Curry portrayed Pennywise. The miniseries event garnered roughly 30 million viewers across the two nights.
On September 8th, 2017, a feature-length adaptation of the book was released in theaters featuring Bill Skarsgård as the demonic clown. Within one week of the film's release, it had grossed more than $130 million.
Pennywise the Clown
On February 17th, 2012, MemeGenerator.net posted a variation on the Pennywise meme, a photo of the clown staring directly at the camera. It has since been the subject of more than 21,700 posts.
Pennywise Gets You
The image of Pennywise in the sewer first appeared in a scene from the made-for-TV movie adaptation of Stephen King's horror novel It. In the film, actor Tim Curry plays Pennywise the Dancing Clown, the corporeal form of a malevolent entity that terrorizes the children of Derry, ME. Pennywise resides mostly in sewers, and in one of the film's most infamous scenes, he lures a child named Georgie down into a storm drain.
On September 4th, 2010, Funny Junk user Notnamed posted one of the earliest iterations of the meme as a Demotivational Poster that read "COMMON SENSE Don't trust anyone that lives in the sewers." The image, shown below, received more than 3,300 views.
Following the release of the trailer for the 2017 remake of It, a new crop of Pennywise-related memes emerged. The two-panel image macro includes the shot of Pennywise peering out from the sewer above a screenshot of a video of a woman crawling into a sewer to rescue a kitten (shown below). The screenshot appears to come from the spanish-language website Schanuzi.com, which used a three panel screenshot in their article about the rescue.
On April 5th, Twitter user @ezeqserra tweeted (shown below, left) the two images together under the caption "¿Querés papas con cheddar de por vida?" which translates to "Do you want some cheese fries?" The following week, on April 12th, Instagram user @skyferreira posted the images to Instagram under the caption "come here kid, i have masochism." The post (shown below, right) received more than 15,700 likes.
In late April of 2017, variations on the Pennywise Gets You meme began appearing on Instagram and meme-focused subreddits. In the variations, Pennywise invites a person into a sewer for something heinous, leading to two panels which show construction workers filling his hole with cement. One of the earliest and most popular examples was posted by Oblivion_Wonderlust to /r/dankmemes on April 25th, 2017. It features Pennywise saying "There are infinite genders" (shown below).
Following the post, several other variations appeared on /r/dankmemes with various popular punchlines within the community. The meme also spread to Instagram that day, when meme account champagneemojis posted a variation about Coachella, gaining over 8,000 likes (shown below, left).
Pennywise Gay Icon
Following the release of the 2017 adaptation, fans of the film and character online proclaimed Pennywise a gay icon. On September 10th, Twitter  user @starkrhodey posted a photograph of Bill Skarsgård with the caption "Pennywise is an LGBT ally: Confirmed." The post (shown below) received more than 340 retweets and 780 likes.
Much like the horror movie character the Babadook earlier in 2017, the character continued to gain notoriety among the LGBTQ community. In the days since the film's release, others began posting about the two characters shipping.
On September 11th, Twitter @kumivenarts posted an illustration of the two walking hand-in-hand, captioning the picture "Pennywise and his boyfriend, The Babadook are off on a date to get crepes and terrorize some kids." The post (shown below, left) received more than 33,000 retweets and 79,000 likes.
That day, Twitter user @AntiBunbun tweeted a picture of both characters with the caption "The Babadook and Pennywise are the next big horror couple… But who wears the better threads?" The post (shown below, right) received more than 40 retweets and 250 likes.
On September 11th, BuzzFeed  published an article about the popularity of the characters shipping. Two days later, on September 13th, Twitter published a Moments page about the response to the Babadook and Pennywise shipping.
Pennywise Dancing, also known as "Pennywise Can Dance to Anything," is a video remix series featuring a camera-recorded clip of Pennywise dancing in the 2017 remake of It dubbed with a variety of humorous songs over the background audio.