That’s probably an octopus or maybe a cuttlefish but not a squid.
Squid can’t be kept captive they die within a day or two. And only octopus have the flexibility to change into “a rock” and can be kept as pets.
But very slight chance its a cuttlefish because I can’t see very well if its completely changed shape or not in pic 2.
Source: I worked in a lab studying octopus and cuttlefish
They move very quickly. They tend to quickly kill themselves by bumping their heads into aquarium walls.
If they don’t die from bleeding, trauma, or infection, or stress, they tend to die pretty quickly from asphyxiation. As whenever they bump into the wall, they get suprised, and spray ink. In an aquarium, the ink stagnates and blocks them from breathing properly.
