It's no secret that Disney films often contain some heart-wrenching moments despite their feel-good nature.
Themes of loss and heartbreak are found in some of the franchise's most-loved animations.
Up sees the main character grieving for his wife, Inside Out had fans in tears when Bing Bong sacrificed himself to save Joy, and even Monster's Inc, which features an emotional goodbye between Sully and Boo, has its upsetting scenes.
But one particularly dark fan theory for the Pixar hit Finding Nemo has left fans feeling crushed.
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The theory was discussed by the hosts of the Just The Nobodys Podcast, the Mirror reports, and gained attention after it was shared on TikTok - in a video with more than 20 million views.
In the opening scenes of the 2003 film, we see clownfish Marlin coming to terms with losing his wife, and all but one of their eggs, in a barracuda attack.
While Marlin touchingly raises his one surviving son as a single dad, disaster strikes when Nemo is captured by divers.
But if that wasn't distressing enough, the 'Finding Nemo Theory' suggests an even darker plot may be unfolding.
Warning that the theory would likely "ruin your day", the podcast hosts explained: "So, we all know the movie Finding Nemo is about a father fish named Marlin and his son Nemo, and it's Marlin's journey in finding Nemo after he was taken by scuba divers.
"There's a theory that Nemo's not real and never existed. It's actually Marlin's imagination because he's grieving over the death of his wife and all his kids.
"And to make everything worse, the word Nemo in Latin means no one.
"Disney's literally telling the audience we have a movie called Finding Nemo but it actually means finding no one, because Nemo's not real."
The host goes onto to explain that Dory, Marlin's sidekick, is "such a good friend" because her short-term memory loss stops her from realising that Nemo is just a figment of her pal's imagination.
It left some viewers devastated as one said: "I should have just scrolled" and another added: "This really did ruin my day what is it."
Others looked to poke holes in the theory, as one argued: "This isn't true. What about the other fish and humans that interacted with Nemo?"
But others said the other fish in the tank at the dentist's office had gone 'insane' from years of captivity and were seeing things as a form of escape, and that Marlin may have imagined other characters to support his illusion of having a son.
