Leeches. They are scary! Their bodies are cold and damp and elastic, and they suck out your blood and stick to your skin so hard you scream in fear while trying to pull them off! My worst nightmare would be to be bitten by lots of leeches until they are bloated with blood, and still they want more 😰😰😰. I might pass out just thinking about it 😨😨😨.
Where I live we get leeches in our backyard during rainy season. During this time I won't ever go out into the yard 😩😩😩.

    Catepie can evolve into metapods, but their attacks are not scary.

    LetThereBeMagic I’ve actually had a leech on my thigh before. I was swimming in a river and crawled out along the muddy side. When I was standing to dry off with my towel, I looked down and lo’ and behold a leech size of my little kid hand on my thigh. I screamed, slapped at myself, and tried to scratch my own skin off. It got off. I never swam in that river again.

        Vanadhi_Lucia I have heard of the Japanese hornet, but I have not researched it much.
        Look at this quote from wikipedia: "An individual hornet can kill forty European honey bees a minute while a group of 30 hornets can destroy an entire hive containing 30,000 bees in less than four hours.[3] The hornets kill and dismember the bees, returning to their nest with the bee thoraxes, which they feed to their larvae, leaving heads and limbs behind. The honey and bee larvae are also taken to feed the hornet larvae."
        WOW, they are vicious. Also, they are very practical. They use almost all of their preys stuff to feed their own. WOW.
        ALSO, I didn't know caterpillars could sting. The venom from the Saddleback Caterpillar can induce "severe symptoms ..... migraines, gastrointestinal symptoms, asthma complications, anaphylactic shock, rupturing of erythrocytes, and hemorrhaging."
        Very interesting.
        Thank you for making me aware of those two creatures.

            I don't know if this comes under bugs but the first thing that comes to my mind about scary insects is lizard.
            I hate them! Yuck Yuck Nasty! Seeing one is enough to give me goosebumps all over my skin. I guess this fear of lizards is because of my childhood experience when a lizard fell over my head. Devastating! Truly!

              Parasites that dig into your skin are the most frightening. Imagine a worm longer than your body spread throughout your innards. They can get in through your ear, mouth, nose or any hole and lay eggs. If you’re writing a novel it would be a terrifying scene to picture a gigantic worm chewing its way out of a body after it’s done growing and leaving larvae that attack the party in their sleep after the mother escapes.

                23DN4L 😱😱😱 ... props to you for being clear-headed enough not to panic. I would have screamed and jumped around like a headless chicken while trying to pull it off.... Now I'm getting goosebumps

                  23DN4L a tick could dry up humans if they are larger, same with mosquitoes. Fleas have this energy storage thing that could multiply their speed. That's why they could easily jump 100x their height, or flip a coin if you put it over them.

                    23DN4L there are also obvious ones like black widows, tarantulas and bullet ants. Black widows and bullet ants could already kill humans from their original size.

                        How about attacked by mob?
                        Mob of insect is more scary than one insect with OP defense

                        checkm8 0.0 I read the entire list and oh man oh man. Thanks for these. I definitely wanna use them in my story; especially the waterbug. Wink wink, you might find it in a chapter soon.

                        But ugh that scorpion arachnid will haunt my dreams tonight. Thanks a lot. (Sobs)

                            bachingchung
                            You’ve listed a lot of good creepers.
                            Fun Fac: The black widows favorite form of birth control is eating their mate after first pregnancy. #tilldeathdoyoupart

                            Bullets ants are the cowboys of the wild world shooting people up with their sting. They don’t even need a gun and hands. Them and fire ants are the reason I’m afraid of all ants.

                                UnderTaker26
                                Indeed! That would be horrific! I almost want to wear earmuffs while sleeping now.

                                    Jinu_June Lizards can be scary. I don’t know if it’s a lizard, but Komodo Dragons creep me out. Big enough to eat me too.

                                        23DN4L centipede! with its many legs, no matter how fast you run, it still can catch you Muahahaha

                                        I can recommend a manga with similar type with your story: Kyochuu Rettou
                                        That manga also tells about a bunch survivor from the wrecked ship that landed on a mysterious island that filled with giant insect

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