This isn’t a rumor or conspiracy theory- Tarzan is Elsa and Anna’s little brother. Chris Buck, the co-director of Frozen (who also worked on 1999’s Tarzan), said that there’s a link between his two beloved movies. Prepare for your mind to be blown.
In Frozen, it seemed like Elsa and Anna’s parents died in a ship wreck. Before that, though, their mother was pregnant and gave birth on the voyage. And, according to Chris Buck, Elsa and Anna’s parents (with their baby boy) did not actually die at sea. They were washed away to an island, where they tried to survive. Elsa and Anna’s parents were killed by a leopard on the island but their baby boy, named Tarzan, survived (to later be raised by gorillas).
Okay so I get what you’re saying- that’s a pretty far fetched theory. But it’s not a theory! That’s what the director of both movies is telling us. But don’t get excited- Tarzan will not make an appearance in the next Frozen movie. Apparently, it was just a fun little secret crossover that Chris Buck wanted to put in Frozen.