The most famous example of how hard it is to overdose on LSD was probably the case where 8 patients were admitted after snorting what they thought was cocaine, but which turned out to be LSD.

The amounts in their blood suggests they each got hundreds of times a normal dose. All eight survived (though it's not clear if they would have without hospital treatment).

The only example I can think of is Tusko, the elephant who was experimented on.

https://www.theguardian.com/science/2004/feb/26/research.sci...