There is a species of animal in my world with a potent venom that can cause paralysis at a specific dosage. This renders a given target unable to move for 24 hours. This venom "locks" a victim's muscles in place; after injection, the target cannot move a muscle until the venom wears off. For instance, if a target was running when injected, after the venom takes effect their muscles would "lock" in whatever position their legs/arms were when running and would stay this way for a full day.

While I am aware of neurotoxins being able to cause paralysis by affecting nerve impulses, as far as I know these neurotoxins cause flaccid or spastic paralysis, such as the scorpion toxin described here. So could a "muscle-locking" toxin such as the one described above realistically exist?

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    $\begingroup$ Not really. To "lock" a muscle, you would need to inhibit ATP binding at the sarcomere level, but that would lock all muscles - including the heart and the lungs. Also, keeping such a state for more than a few minutes would lead to tissue death and rhabdomyolisis. I'm afraid you have to choose between flaccid and spastic paralyses. $\endgroup$
    – LSerni
    Feb 3, 2022 at 22:28
  • $\begingroup$ Agree with the comment, it's always a induced traject, it cannot be stopped halfway. Also I'd like to add scorpions are not the only species that produce this venom, Theraphosid spiders like tarantula have venom that can induce cramp [1]: en.wikipedia.org/wiki/Tarantula [2]: pubmed.ncbi.nlm.nih.gov/33493497 $\endgroup$
    – Goodies
    Feb 3, 2022 at 23:00
  • $\begingroup$ There are paralytic venoms, but they kill you long before 24 hours. You would be so screwed up after 24 hours of locked muscles anyway that it may as well be fatal $\endgroup$
    – user71781
    Feb 4, 2022 at 1:15
  • $\begingroup$ Even if such venom can work and is plausible, there's a small problem that the heart is also a muscle... $\endgroup$ Mar 11, 2022 at 18:07

2 Answers 2



Muscles want to be in one of two states - lengthened or contracted. As you say, certain toxins or bacteria can cause spastic paralysis, where the muscles move to "contracted" in an uncontrollable fashion (see tetanus as a longer-term example), and others can cause flaccid paralysis (eg. curare), but if you're in motion, your muscles are in transition, and that state cannot be made to persist, because "in transition" is not a state which your muscles can "understand".

(Scare quotes because muscles cannot understand anything, but it is a useful descriptor.)

Muscle tension is activated/deactivated by the presence of neurotransmitters at sites in a muscle cell. While certain muscle groups are capable of isometric tension (and therefore static paralysis), the vast majority are not.

It would also go without saying that even if it were possible, this would cause death in its victims very quickly, as even if cardiac muscle were excluded from systemic muscle paralysis, the diaphragm would not be, and the victim would asphyxiate well before a day had passed.

  • $\begingroup$ 'Scare quotes' take single quotation marks. Otherwise it's an actual "quote". $\endgroup$
    – Mazura
    Feb 4, 2022 at 6:57
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    $\begingroup$ @Mazura Never heard of scare quote before, so I looked it up. Wikipedia says "Whether quotation marks are considered scare quotes depends on context; scare quotes are not visually different from actual quotations." Which culture/area uses the distinction you propose? $\endgroup$
    – user91641
    Feb 4, 2022 at 8:51
  • $\begingroup$ @ooak --- Perhaps the single quote variety is really only 'mildly frightening quotes'? $\endgroup$
    – elemtilas
    Feb 4, 2022 at 14:44
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    $\begingroup$ @elemtilas Hmm, and triple quotes for '"utter terror quotes"'? ;) $\endgroup$
    – user91641
    Feb 4, 2022 at 15:33
  • $\begingroup$ The Chicago Manuel of Style says (to actually use double for scare) however, I'm old : "A once-common practice, now usually confined to etymological texts, was the use of double quotes only for extracts and dialogue and single quotes in all other cases where quotes were called for." I was pretty sure this is ELU's preference but I can't find it. Doesn't help the that the font sucks and all we have is apostrophes that go straight up and down. $\endgroup$
    – Mazura
    Feb 5, 2022 at 3:00

jdunlop's answer above is a pretty solid no, but a venom produced by the body and spread via stinger that locks the muscles in either the spastic or flaccid position depending on which state the muscle is closer to could work if the venom hijacked the dragon's nervous system. This could result in an eerie effect where the muscles spasm at the moment of injection before locking in place as they go to their spastic/flaccid position.

The poison would also not affect them instantly, instead starting at the limb the venom was injected into and spreading through the body via the bloodstream. This would result in the victim doing a creepy involuntary imitation of a 'turn to stone/gold' effect as the venom spread through the bloodstream, paralyzing one body part at a time over the course of a dozen seconds or so.

The 24-hour thing is a stretch of the imagination though, as the venom would have different durations depending on the size of the victim. It would last longer on smaller victims and shorter on larger victims.


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