The squid ink is not toxic and actually the squid ink is safe even for human consumption.
I've heard that people use squid ink in dishes and food and use the squid ink in things such as sauces and other recipes.
I personally would not want to eat the squid ink but some people do and even the squids natural predators eat the squid ink and it's not toxic.
The squids do contain some poisonous venom but that venom is different from the squid ink.
The squid ink is consumed by many people in some places but I've never eaten it and never will.
It just seems gross to me.