Squid have 3 brains and at least 2 hearts.
However Octopuses do have 9 brains but octopuses are different from squid.
The octopus has 1 main brain and then the octopus has other brains in each of their 8 arms.
So the 8 other brains of an octopus are 1 brain in each of the octopuses 8 arms and the other brain that controls the central nervous system.
An octopus and especially the giant pacific octopus has 3 hearts, blue blood and 9 brains.
The octopus has a cluster of nerve cells that connect to those brains that control the movement of the octopus.
It's amazing if you were to open up an octopus or a squid you'd be able to see the amazing insides and operation of squids and octopuses.