Hyper Mode is a new special mode that monsters can be locked into. As the name suggests, these monsters have been discovered by the hunting guild and wycademy to be locked in a perpetual stage of rage. They are far more aggressive, hit really hard, attack fast, and are unrelentingly angry . Maybe they should see a therapist for that.
Hyper Mode monsters are easy to identify by the red cloud that constantly shifts around them. At certain points in the battle, the red cloud will become particularly concentrated and intense around particular body parts. If the red cloud flashes and makes a crackling noise while you are within the hitbox, you will be defeated in one hit regardless of defense or current health . That's right, it's a one-stop shop to the base camp being carted by cats! However, if you successfully hit the body part that's surrounded by red aura without getting hit, your hunting arts charge faster. It's a true risk and reward system. Beware!
All monsters except Elder Dragons, small monsters, and some of the smaller boss monsters such as Volvidon, Lagombi, and the -dromes can be afflicted by Hyper Mode. So what's your reward for going through hell to bring them down? Hyper monsters will give you special hyper materials ! All weapons, if you want to upgrade them to their final form (unless the monster the weapon comes from can't be hyper, as listed above) will need materials from the Hyper monster. I know I know, it sucks, but you as the hunter ought to rise to the challenge with enthusiasm and valor!
There are special R Series armor sets you get as well. Unlike Low and High Rank armors, hyper monster armor is particularly defensive with other nifty perks. Additionally, scraps from hyper monsters can be used to make especially powerful armor and weapons for your Palicos! Definitely makes Prowler Mode even more awesome. So be sure to get out there and get good at defeating those Hyper Monsters! Beware the flashing red zones, learn when they tend to flash (it's not random), and plan your movements around that.