- “You see the peaceful Puka Michuna tribe? With the touch of this button here, I could end 400 innocent lives, their only crime is that they are still living. The choice is yours, do they live or do they die?”
- ―Prince Joachim[src]
Prince Joachim is one of the two main antagonists in Disney's 2021 film Jungle Cruise and is based on the historic figure of the same name. He is a wealthy German aristocrat who seeks the Tree of Life to help the Germans win World War I.
Prince Joachim often comes across as a pretty polite and even quirky man. Underneath the polite façade, however, Joachim was a very greedy and murderous man, which was proven when he initially held McGregor hostage and initially showed him a fair bit of hospitality, only to threaten to kill a whole tribe of 400 people just to strongarm him into telling him where Lily and the arrowhead were. As for his greed, this is especially apparent when he betrays Aguirre and his men by going back on their deal. Specifically, he promised them that if they helped him, he would share the petals of the Tears of the Moon with them so that they could lift their curse, only to betray them by killing the bees they were using to convey information, so that they wouldn't be able to find it once he knew the location himself so he could horde more of the petals for his own means.
Despite all of this, it's worth noting that Joachim never engages in cruelty or murder for its own sake. For example, once MacGregor told him what he needed to know with regards to where Lilly and Frank were, it's highly implied he left the tribe he threatened alone since he got what he wanted. Also, when pursuing the trio on Frank's boat earlier in the movie while in his submarine, he caused surprisingly little collateral damage despite chasing them through a port area, with the only significant damage being the destruction of an empty building owned by Nilo, with even that being caused by Frank redirecting a torpedo he fired underneath the boat. Another notable point is that on the one hand, he quickly murders a few members of the society who were planning to give him the arrowhead in exchange for a considerable sum of gold when one of them accidently reveals his name in front of a few others present, which was supposed to be kept confidential. Conversely though, he was quite forgiving and merciful towards the member he was making the transaction with for one, allowing Lilly to steal the arrowhead, and two, carelessly revealing his identity to the others. This only further emphasizes that while quite ruthless and having no qualms with killing or threatening innocent people to get what he's after, he does so specifically when it's a means to an end, but won't go out of his way to do it either when he doesn't deem it necessary.
He is first seen in London when Lily narrowly avoids him. A few minutes later, it is revealed that he has made an arrangement to receive the arrowhead, but Lily manages to steal it before he can pick it up. He is later seen in his submarine, trying to sink Frank's boat, as Lily and McGregor were aboard. He failed, but he destroyed Nilo's fleet and company.
Joachim locates the cursed conquistadors and Aguirre, whose bodies turned to stone due to them traveling too far from the river, and have been infested over time by tree roots, snakes, and insects. Joachim frees them by diverting the river, and offers to help them break the curse if they help him retrieve the arrowhead.
As McGregor was injured, and hence, left behind, Joachim captures him and threatens to destroy a tribal community of 400 people if he does not tell him where Lily and the arrowhead were, causing McGregor to tell him where they are. After Frank and Lily find the entrance to the place the tree of life resides, Joachim captures the two of them. Joachim breaks his arrangement with the cursed brigands in order to keep the petals for himself, but Frank, Lily, the Germans, and the Spaniards all converge on the tree. Joachim threatens Lily, saying McGregor will die if she does not give him the petal, but Aguirre ties him up with his snakes, saying royalty can't be trusted. As Joachim did not get the petals of the tree of life, Aguirre decides to get it himself. As Aguirre and Frank fight, Joachim threatens to kill Lily and McGregor, but McGregor stands up to him and punches him, causing him to get knocked into a wall. As he curses in German and starts to get up, a large boulder falls on him, crushing him to death.
- Joachim's submarine might be a tribute to the defunct Disneyland Tomorrowland attraction Submarine Voyage.
- In real-world history, Joachim spoke no English while in the film he does.
- In real-world history, Joachim died by suicide in 1920 while in the film he is killed in 1916.
- Princess Augusta Victoria of Schleswig-Holstein is his mother in real life, and Kaiser Wilhelm II is his father.