When all hope was lost for the new Losers' Club in the It: Welcome to Derry finale, a surprising presence helped them bury the entity's dagger and trap it for another 27 years. Rich Santos' (Arian S. Cartaya) adorable cameo in the HBO prequel series' finale became one of the most heartwarming moments from the series, one where the fallen knight helped his friends defeat Pennywise from the afterlife.After Rich sacrificed himself in the penultimate episode, showrunner Andy Muschietti wanted to bring back the character for the finale. Cartaya's cameo was written just days before the filming of the It: Welcome to Derry finale, with Rich's iconic finger-flipping moment (to Pennywise), an impressive improvisation by the young actor.In an interview with TV Line, Muschietti revealed the details about this unscripted moment:''The middle finger came as the result of improvisation at the end, and since [Arian] is a phenomenal kid and a great actor, of course he was down."More on Rich's cameo in It: Welcome to Derry in our story.The cameo that changed Pennywise's fate in the It: Welcome to Derry finale View this post on Instagram Instagram PostThe It: Welcome to Derry finale was an intense hour in HBO's prequel series, which saw the Loser's Club unite to bury the remaining shard of the entity's comet in Deadwood. This task might look easy, but Pennywise had not only plunged the titular town into a thick, depressing layer of fog, but, as Rose had predicted, the dagger was also resisting and manipulating the kids, making the mission harder. With Taniel dead, the military chasing after Dick & Leroy and the entity just inches away from its freedom, all hope was lost until our fallen knight showed up.Rich's death was one of the most tragic plot twists in It: Welcome to Derry Episode 7, after he sacrificed himself in The Black Spot fire to save his crush and friend, Marge Truman. While Rich's friends were devastated by his death, his surprising cameo changed the fate of Pennywise in the final moments. Just when the monster was about to reach the final point at Deadwood, which would have guaranteed his freedom, Dick saw Rich's spirit running across the frozen lake to help his fellow losers. On his way, he shows the finger to the entity and helps his friends bury the dagger, ensuring Pennywise's hibernation for another 27 years.Rich's magical cameo became one of the most talked-about moments from the It: Welcome To Derry finale, which was improvised and added into the final script mere days before filming. As Muschietti told TVLine:"We did a lot of improvisation in general, and that's one of the things we created on the day, or a couple of days before. And I'll tell you, the [resurrection] of Richie was something I came up with probably in the last few weeks [of production].''Why does Rich's cameo matter in the It: Welcome to Derry finale? View this post on Instagram Instagram PostWhile Rich's cameo was a heartfelt moment, it also holds thematic significance in King's horror verse. Ever since Dick's harrowing confrontation with the entity in the sewers, where It forced him to open the box and unleash evil spirits, the talented airmen had been plagued by voices in his head. These voices were partly calmed when Rose offered him Maturin tea but Dick witnessed Rich's spirit help the Loser's Club trap Pennywise.Muschietti detailed Rich's cameo in It: Welcome to Derry as:''In a world where we have someone — Dick Hallorann — who sees dead people, and in a world where we lost one of our beloved heroes, which is Richie, I thought of giving a little comfort to the audience by bringing him back."The young knight's cameo reiterated the group's unity and helped cut through the tension in the final moments, as the showrunner added:"We see the monster crawling, and it's a very anxiety-ridden ending, and that was allowed by the presence of Rich — the Loser that was not there.''While Rich's friends were unable to see him, they certainly felt his presence in the form of an extra pair of hands. Rich's cameo cemented him further as a fallen hero in It: Welcome to Derry, who helped his friends even in the afterlife.The It: Welcome to Derry finale is streaming on HBO Max.For the latest scoops on your favorite TV shows and movies, follow SoapCentral.