When Making Takoyaki, Why Do Some People Cut The Tip of The Octopus Tentacles?
Many Japanese believed the tip of the octopus tentacles had poison, which was a myth.
So, those who believed the myth was true, cut the tip-off, while others did not.
Growing up in Japan, I have heard this myth, through my mother, or friends. I too thought it was true (or more like never doubted), until when I learned it was not.
Why such a myth? One theory is because the suction cups attract many bacteria, some thought was poisonous, which led to the myth.
Be assured when you cook the octopus, you will kill all the bacteria.
Many bacteria in suction cups are also one of the reasons why most Sushi/Sashimi octopus is cooked.