Doctor Octopus' Tentacles were a group of four robotic tentacles that connected to Doctor Otto Octavius' brain and spinal cord through brain-computer interface as a means to control them. They were originally experimental tools that he used as an "assistant" in his lab to further revolutionize human technology (including atomic physics). After he turned his life to crime, Octavius named himself Doctor Octopus (fitting with the fact that he had eight limbs: four tentacles, two arms, and two legs) and used his mechanical appendages for evil.
These tentacles served as the true main antagonists of the 2004 superhero film Spider-Man 2 due to their possessed sentience as villains unlike their comic book and animated counterparts that were merely mindless limbs and tools for evil, while their creator is the secondary main villain although he changed himself to anti-hero in the end.
These tentacles' physical appearance shared many things in common with the other incarnations in comic books and other Spider-Man related medias: All are appeared in four numbers, could stretch over 20 feet, had pincers on each of their tip (usually in form of 2-4 digit claws), and were made from highly resistant alloy.
For Doctor Octopus' Spider-Man 2 incarnation, his mechanical tentacles are constructed from alloy that created from successful fusion which resulting the material that used for their creation became impervious to heat and magnetism. In addition, the tentacles also had an inhibitor chip that installed on the harness where the tentacles attached on as well as part that connected to Doctor Octopus' nervous system on his spinal column which allowed him to control them in the same way he controlled his limbs. After the accident however, the chip was ultimately destroyed.
Capabilities and Means of Controlling
Unlike other versions of these tentacles whom originally showed being controlled through brain-computer interference before being slightly damaged due to the accident which fused them with the mad doctor's body (permanently or otherwise) and eventually enabled to be controlled via telephatic means, these mechanical tentacles' incarnations were controlled by Ock's own mind from start due to his nervous system were connected to the tentacles via the tentacles' harness. Because the means to control these tentacles also involving the usage of artificial intelligence that would made his mind vulnerable, Doctor Ock created inhibitor chip to keep his mind intact.
Unfortunately, when his experiment went wrong, it's revealed that the inhibitor chip's function was not only to keep his mind intact, but also to supressed the tentacles's sentience that manifested from the very artifical intelligence that used to made them moved as the doctor wants (something which he didn't realize until the chip's destruction).
Upon the inhibitor chip's destruction, the tentacles' sentience eventually activated after being suppressed by the said chip. This was shown where they persuaded the mad doctor to finish his destructive projects and actually "yelled" in anger and sadness along with their master after he found out that his wife was accidentally killed by his own hands. Their manipulation and sadistic traits are originated when Octopus' inhibitor chip was destroyed. The chip made it so that he had complete and utter control over the arms, so its destruction gave them the high intelligence to almost completely take over Octopus' already unstable mind and turn his crimes into even more serious felonies.