Toxic Plants - end it like Socrates....

[LittleJem]

I'm not sure if any of these plants would make for a fun exit - but effectiveness wise, they are on the money:

10 of the World's Deadliest Plants — And How They Kill You

Be careful what you touch, and what you eat. Some vegetation can snuff out your life as surely as a venomous snake. There are hundreds, if not thousands, of poisonous plants in the world, and some of them are deadly.

io9.gizmodo.com

Also this: https://www.spaink.net/suicide/suicide_poison_natural.html

 

[Bardia]

They're all agonizing and miserable ways to die, though.