Fidel Castro was beloved by the people but hated by the elites. Naturally, the only people in Cuba that had money wanted to take him down, but they overlooked how difficult this might be.
According to recently released documents from the former director of Cuba's intelligence service, there were more than 600 attempts to either kill or destabilize Fidel Castro. All of these attempts were spearheaded by corrupt government agencies masquerading as militant groups of citizens.
Castro saw right through this facade, as he was a man of the people, and virtually no Cuban citizens were siding with the corrupt government or any other government system that had their hands in the pockets of other wealthy Cuban officials.
However, this did not stop Castro from accepting the complaints from these individuals and confronting them directly, but somehow he was able to thwart every single attempt at his assassination.
There were a ton of direct attempts at his assassination, including poisoning, snipers shooting at him, bombs, mail threats, etc.
However, the most creative ones were notably easier for him to see through.
For instance, there was a time where Castro was poisoned with thallium in an attempt to make his beard fall out (it didn't), there was another time when he was dosed with LSD to make him say strange things on national television (he didn't, but later stated that he was, in fact, super high).
Officials poisoned his diving suit with anthrax (somehow this didn't work), they rigged one of his cigars to explode (it was a dud), he was even seduced by a hired "supporter" who was paid to kill him. Castro eventually found out about her intentions and told her to carry out her duty, she didn't have the nerve to do it.