I want this to be a message to all the casuals out there, beating Tequatl is very possible.
My guild and I regularly run Guild Wars 2 content and post walkthroughs for the community. We jumped on board to run the Tequatl fight and recorded a guide for those having trouble.
Our biggest recommendation to those struggling? Give this some time as people are still learning the fight and the mechanics. Additionally, joining a large organised group can definitely help you. Many guilds are posting adds in the forums, in Lions Arch, and even in Sparkfly Fen. With a little information about this encounters mechanics you can easily contribute to larger organized group, or even assist a disorganized overflow to prevail against this beast.
You may not win tonight, tomorrow or the night after that, but a win is possible, and just takes a great deal of team work. As casual gamers we struggled many times, but finally found our groove, as well as a really good group to run with. Good luck to you all, here’s what we learned, we hope it helps.