The Theory: At the start of Frozen, Anna and Elsa's parents are shown being killed in a boat crash - but their destination is never mentioned.
It was then theorised by many that the parents were travelling to the wedding of Rapunzel and Flynn Rider - the main characters from Tangled - but a violent storm took their lives before they made it.
Then, more fuel was added to the Tangled-Frozen-connection fire when Rapunzel and Flynn were spotted at the end of Frozen, attending Elsa's coronation. Do the two movies exist in the same universe?
The Rejection: Well, not according to Mandy Moore, who voiced Rapunzel in Tangled and its subsequent TV series.
When asked about the connection in an interview with TVLine, the actress said "I don’t know if we need any crossovers at this point", before adding "there is no connection as far as I know".
This theory has also been disproven by fans many times over the years, making the appearance of Rapunzel and Flynn at the end of Frozen... nothing more than a cute easter egg. Sorry to burst that bubble.