Dododex
ARK: Survival Evolved & Ascended Companion
Easy bio toxin: Just find one near the shore, aggro it and swim to the shore…

Easy bio toxin: Just find one near the shore, aggro it and swim to the shore, making shore its following you. Once your on the shore wait for jellyfish to be on the edge of shore and just stab it with your spear / pike. You get like 20 - 30 bio toxin, but 1 spoils in about 40 minutes. I find it really useful to just go harvest bio toxin than use narcotics to keep a tamping Dino asleep, so you can use all your narcotics on tranq arrows or tranq darts. Oh and finally once you reach a high enough level (I think around level 90) you can learn the shock dart which uses the bio toxins, and 1 - 3 shots most Dinos.
More Cnidaria Utility Tips
Basically no utility except biotoxin, only go after them with weapons that have long ranges and MAKE SURE YOUR TAMES WON’T CHASE THEM!!! When I was a noob I watched my entire dilo pack run after them and watched as they were all slowly and brutally murdered, and I’ll probably lose more tames to those monsters later. If a troll was a creature, it would probably be this one. One ☝️ = one RIP for every tame lost to these.
These guys are annoying when i step in the water they attack and kill me. I know this jellyfish species its the deadly box jellyfish that that kills you in the ocean. Me and my carbonemys are swimming in the water to find dossiers and box jellyfish attack me and dies. 1 like= remove box jellyfish