a natural weakness to sonic attacks and heat-based attacks, which Knull unintentionally gave them while they were being forged. However, symbiotes have a growing resistance to sound and fire due to their evolution.
Despite his hatred of Spider-Man, Venom has a twisted sense of morality, avoiding harming anyone he deems to be innocent and even performing heroic deeds. However, it is never clear how long Venom's darker impulses can be held in check.
It's varied from fire alarms to Reed Richards's sonic weaponry in classic comic book fashion. I imagine that they all mess with Venom, but the symbiote is strong enough to power through most and it depends on the host's capabilities as well.
The movie doesn't clearly state why, but Venom is probably afraid of Carnage because Carnage doesn't have the moral restrictions that Venom does. They are alien symbiotes. This means they need another living host to bond with if they're going to survive long-term.
One of those is sound waves. Extremely loud sounds (or extremely high frequency sound waves) can shock the symbiote, and even cause him to separate from his host. Spider-Man discovered this not long after meeting Venom.
Eddie Brock's symbiote needs chocolate and brains for an important reason. Sony previously showed the symbiote's love of chocolate and brains at the end of the first film, with Eddie trying to suppress Venom's hunger for humans with the sugary substance. However, Venom ends up biting off a mugger's head anyway.
The Venom symbiote has two major weaknesses - sound and fire. Loud noises cause the symbiote to writhe in pain. That's how Peter Parker originally freed himself of the symbiote.
Weaknesses. Sonic Vibrations: Extremely loud noise in the range of 4000-6000Hz and intense sonic vibrations severely injure Venom, so much so that elongated exposure can "un-bond" the Symbiote from the Host.
Weaknesses. Heat and Sonics: Like most symbiotes, Scream is vulnerable to intense heat and sonic vibrations, although it has been shown to be unharmed by hellfire while bonded to Andi Benton as long as she allows it.
Since his debut however, Venom has evolved into an antiheroic figure, slowly distancing himself from his initial goal to ruin Spider-Man's life to try and do good instead, even putting aside his differences with and helping Spider-Man at times.
Venom is portrayed by Tom Hardy in the MCU with a height of 5'9” (1.75 m) though his size is variable. The comic book height of Venom is 6'3” (1.91 m). Venom is the name for a fictional human host, most famously Eddie Brock, combined with the alien symbiote that gives him powers.
Venom sees Holland's Spider-Man on TV, licking the screen and remarking that "He looks delicious." The implication was clearly that the Symbiote wanted to go after Spider-Man.
Kasady is also immune to the effects of all Earthly diseases and infections as long as he remains bonded with the symbiote. Like Venom, Carnage is vulnerable to sound (to a much smaller degree than Venom) and heat (to a much larger degree than Venom), and is undetectable to Spider-Man's spider-sense.
The Venom symbiote's animosity toward Spider-Man stems from its initial bond with him. In the comics, Spider-Man rejected the symbiote when he realized it was trying to permanently bond with him, and he removed it. This rejection left the symbiote with a strong sense of betrayal and anger.
For example: When the symbiotes take over a human body, the body convulses, twists and contorts in a visually disturbing and very scary way. When the symbiotes are in their alien form, they are terrifying, huge and monster-like creatures with glowing eyes and jagged sharp teeth.
Venom's favourite food used to be human brains. Eddie's secret love for chocolate, however, overtook it, making chocolate of all things to become Venom's favourite food. (Some comics show that Venom has a craving for Tater Tots, Hash Browns, and food from McDonald's.
Venom's symbiote has explained on many occasions that the Klyntar planet is practically devoid of emotions, yet over time he knows that he forms genuine love for Eddie. Venom bonds more with Eddie and experiences guilt, jealousy, and sadness over his other half.
By eating Carnage, Venom is effectively returning his spawn back to his former "unborn" state within Venom's mass, not taking anything he didn't already have into his cells.
(Venom(2020)issue#24) He fears losing his son, a fear related to his previous fear of being completely alone. He fears being left alone with his own thoughts, he fears living with no one at his side, that's why he was so dependent of the symbiote back in the day.
Venom came to empathize with Eddie's status as a "loser", eventually deciding to turn on its own kind and save the Earth from being invaded. The symbiote ultimately agreed to work alongside Eddie as a vigilante, to only hurt bad people despite its own confusion of how it can tell the difference of who is good or bad.
However, you might've noticed in Marvel's Spider-Man 2, the villain is completely invulnerable to fire. As explained in an IGN interview, this isn't a continuity error, but rather an intentional design choice made in service of intuitive gameplay.
During the mini-series Venom: The Hunger, Eddie learns that the Klyntar symbiotes crave phenethylamine, a chemical developed in the brain. Eddie's refusal to let Venom eat brains leads to the symbiote starving and abandoning Eddie. Fortunately, Eddie finds an alternative source for phenethylamine: chocolate.
Venom Quickly Transitioned from Spider-Man Villain to Lethal Protector. Eddie Brock was created by David Michelinie and Spawn creator Todd McFarlane, with his first true appearance being in Amazing Spider-Man #298.
Todd MacFarlane wanted Venom to be massive, or at least much larger than Spider-Man. This was achieved with Eddie Brock Jr. also possessing a hulking physique, and thus the correlation was made that the symbiote also became a brute with Eddie as its host.
