Is the only way a Symbiote can truly die, by choice?

Question

I found this image on Facebook recently.

Did Venom ever say this, and if he did, is it true?

I've included the MCU tag because I know he's in Spider-Man 3, but it's been a few years since I watched it and I refuse to watch it ever again.

Answer 1

Venom did say it...

In Web of Spider-Man Super Special (1995), the fifth and last issue of the "Planet of the Symbiotes" arc.

But he was certainly wrong

The nature of the Symbiotes has been subject to a number of retcons, as with most things Marvel. However, in most media Venom (and other symbiotes) can die.

For example, in Spider-Man 3, Venom was killed by a Pumpkin Bomb.

And in any continuity, it seems difficult to believe that with all the cosmic entities in the Marvel Universe—the Phoenix Force, Death, the Beyonder, Eternity, Galactus, the Fulcrum and so forth—the Symbiotes are truly invulnerable to destruction.

Answer 2

As the other answer states, this was said, but is very incorrect.

Other ways to kill off a symbiote that can be accomplished are:

Comics:

• Sonic weapons: This causes disruption to their particles if severe enough. The symbiote is liable to be ripped off of any host due to this and all the resultant pain - and if the attack is kept up with them being unable to escape, this will kill them.
• Immense heat/fire: Heat, fire, explosions - this will destroy them and they can have very adverse instinctual reactions.
• Starvation: They need Phenethylamine and often don't do great without hosts (their being rare exceptions who can manage hostless). The Hybrid symbiotes were not doing too well at all when they went too long without a host and the Venom Symbiote also started dying in an alt universe "Marvel Zombies" - starving because their host was dead.
• Chemicals: Never gone into specifically what sort, but at a point Eddie Brock having a concoction of chemicals in his body due to past experiences in the 2016 series, started causing the Symbiote to deteriorate to the point that help had to be sought.
• Anti-Venom Symbiote: Exposure to this, is the equivalent of dunking a human in hydrochloric acid. It will burn away the symbiote until there is nothing less - not even traces in a hosts blood (which is important)
• Being Eaten: Being eaten to fulfil someone else's hunger, can also kill them. Along with their own cannibalistic tendencies, there's also an entire race called the "Xenophage" which preys on them.
• Psychic Attacks: As seen in the Planet of the Symbiotes arch.
• Assimilation: "Poisons" are a race of beings that assimilate bonded symbiotes and their hosts into them - upon which, the symbiote is gone.

Movie Exclusive:

• In the Venom 2018 Movie, the symbiotes cannot tolerate Earth's atmosphere without a host that can - and so will suffocate if exposed while unbonded for too long.

Important Note:

As you will notice, the recurring theme here is destroying their particles until there is nothing left of them.

And there must be nothing left of them, to be completely sure of a dead symbiote every part of them must be dead.

Them being a bit like the "Thing" in the regard that there is no part of them "more" important on the other - you could completely incinerate a main body of a symbiote and it's host, but that tiny sliver of a tendril over there which was just severed? Could and would sliver away and after eating/assimilating enough - they recover and regain the mass they lost.

There's also how - if bonded long enough, they leave trace amounts of themselves in their host's bloodstream.

Meaning, that they can hypothetically recover from their "destruction" if a host is alive - a particular example of this being Carnage/Cletus: Red (the symbiote) having been destroyed in various ways before such as being eaten and only coming back as a result of Cletus not being destroyed.

Then there's the generational thing: All these weaknesses apply to symbiotes, but the higher the generation the more resistance they have to it, as they get stronger and adapt with each new progeny in the line.

So, to put it one way - Venom Symbiote would be easier to destroy with sonic weapons than it's progeny the Carnage Symbiote would be which in turn would be more vulnerable than it's progeny the Toxin symbiote.

Essentially, there are various ways to kill a symbiote - but it's still ultimately very difficult, with how adaptive and resilient they are.