As was the case with Monster Hunter: World and its frequent updates, Capcom has also vowed to continually update Monster Hunter Rise. The first update for Monster Hunter Rise just released and with it comes a slew of new content including a fight against the elder dragon Chameleos.
Prep, Weaknesses, and Hitzones
Chameleos does not use any elemental attacks, so players do not have to worry about making sure their resistance to a particular element is high enough. However, Chameleos does use poison, so players will want to consider getting some poison resistance on their armor. If they don't want to do that, then bringing some herbal medicine or antidotes will be key. Flash bombs can also force Chameleos out of their invisibility, so players may want to bring some of those too.
In terms of Chameleos' elemental weaknesses, it is weakest to fire and dragon with fire being slightly more effective. It takes some additional damage from thunder damage, but water damage and ice damage are not recommended. As always though, elemental damage, in general, is more important on fast attacking weapons like dual blades than slow ones like greatswords.
As for hitzones, as with most monsters, the head is a good place to attack for all weapon types. For severing and blunt weapons, Chameleos' forelegs are also good options. Shot type damage isn't very effective on the forelegs. Shot type damage should focus on the tail instead as a second option as it has the same hitzone values as the head.
Status effects don't have much effect on Chameleos. It resists poison, paralysis, sleep, and exhaustion. It has a one-star susceptibility to stun, waterblight, thunderblight, and iceblight. Blast and fireblight are rated two stars in terms of efficacy.
Fighting Chameleos
Chameleos has two major gimmicks. To start with the first, Chameleos' ability to turn invisible can take two different forms. Sometimes it only goes semi-transparent and a purple sheen can still be seen, so it's easy enough to spot where Chameleos is. It might be a bit difficult to target specific parts, since it kind of looks like just a mess of purple in that state, but at the very least it's easy to keep track of the monster.
However, Chameleos can go completely invisible. At this point, it's difficult to track so players should keep moving to avoid being hit by an unseen attack. Gunners can attempt to fire shots into the nothingness to see if they manage to hit Chameleos, but that can still be risky.
While often used to bring a monster like Rathalos down to the ground, using a flash bomb can force Chameleos to reappear. Notably, the flashing effect around the head of Chameleos to indicate it has been affected by a flash bomb will remain if it goes invisible again, meaning it can be tracked by this visual effect. As the hunter's notes state as well, breaking Chameleos' head will stop it from going invisible.
As for its second gimmick, Chameleos can steal players' spiribird pollen from their petalace. It will usually do this by lashing its tongue out at players, but it also has a physical charging attack that can also steal the pollen. A random stat increase the player has received will be removed from the player and Chameleos will be buffed. While perhaps not as annoying as Chameleos' ability to steal items from players in past games, this is still something to watch out for.
Chameleos' poison attacks are especially potent; in fact, they're so potent that the status ailment they inflict is actually not standard poison. While Monster Hunter Rise does not seem to explicitly name it, the icon used for the status condition is the same used for the venom status condition from Monster Hunter World: Iceborne. Regardless of what it's called, it's a type of poison that will drain hunters' health much faster than standard poison.
Chameleos can inflict venom in a few different ways. It can spit out globs of poison at hunters and it can use a poison breath attack. The balls of poison can leave lingering clouds of poisonous mist. Chameleos occasionally will use its wings to direct the poisonous mist towards the players. In one move specifically, Chameleos will create a circle of poison mist and send it outwards and players will need to be ready to run or use wirebugs to jump over the circle when they see that it has formed. Chameleos can also release what appears to be a type of fog to cover the arena. This doesn't really affect visibility in any meaningful way and Chameleos leaves itself open to attack while it breathes it out.
As is likely expected, Chameleos also has additional physical attacks. Aside from the previously mentioned charge that can steal spiribird pollen, Chameleos will also slam its body onto the ground. Sometimes it will do this twice in a row. When it's done, however, it will go slightly invisible and stay down for a while. This is a good opening to attack assuming hunters can find the body part they want to target.
Players standing behind Chameleos are not safe though. Similar to Diablos, Chameleos can slam its tail down onto the ground and send boulders flying quite a distance. It will also do this repeatedly. It's possible to stand in the spaces between the boulders, but it's probably a better idea to just get out of the way.
There are two attacks of Chameleos' that will trigger a callout from the hunters. In one, Chameleos will spit out globs of poison all around it before breathing poison in front of it twice. In the other move, Chameleos will breathe poison in front of it once, turn invisible, fly to a different part of the arena and breathe poison in front of it again. Neither is particularly hard to avoid, but the hunter callouts give players time to prepare for them.
Monster Hunter Rise is now available for the Nintendo Switch. A PC release is slated for 2022.
Source: Monster Hunter Wiki