SHORT VERSION: Ignore Toss Filth, strafe slightly to avoid Bananarang, run away from or CC rare in response to Going Bananas.
The Yowler is one of 56 rares on Pandaria. The achievement Glorious! requires you to kill every rare on Pandaria.
The Yowler is also one of seven Hozen rares on Pandaria (one in each zone). The other Hozen rares are Mister Ferocious (The Jade Forest), Bonobos (Valley of the Four Winds), Spriggin (Krasarang Wilds), Scritch (Kun-Lai Summit), Ik-Ik the Nimble (Dread Wastes), and Major Nanners (Vale of Eternal Blossoms).
Lastly, The Yowler is one of eight rare spawns in Townlong Steppes. The other Townlong rares are Eshelon (Jinyu), Lith'ik the Stalker (Mantid), Norlaxx (Mogu Sorcerer), Kah'tir (Mogu Warrior), Yul Wildpaw (Pandaren), Siltriss the Sharpener (Saurok), and Lon the Bull (Yaungol).
The Yowler shares most of his loot table with the other rares in Townlong Steppes, who all drop itemlevel 440 blue-quality necklaces. Additionally, you have a 20% chance to get a Small Bag of Goods, which contains a couple of stacks of trade goods items used for various professions along with some extra gold.
All Pandarian rares drop a special rare item, and in Townlong Steppes, the rares drop blue-quality bags of loot similar to the Small Bag of Goods but far more powerful. The Yowler's rare item is Big Bag of Food. It is a very valuable item because it contains a full stack of Pandaren Banquets and Great Pandaren Banquets, which are worth quite a bit of money. It also contains a few Banana Infused Rums, but those are more of a fun/silly item than a valuable one.
The Yowler spawns in a cave underneath a massive tree. The entrance is facing north, and there are no nearby enemies.
The Yowler has three abilities. His first ability, Toss Filth, is uninterruptable and cast so frequently that it is not worth trying to avoid with CC effects. His other two abilities are much more unfriendly.
Bananarang is a move that he casts towards your position that summons a “Bananarang”, which travels in a straight line out about 30 yards and then comes back in a straight line for about 60 yards. It hits extremely hard and is critical to avoid. Two hits from a Bananarang means death for most players, and even one hit means you will need to focus a bit on self-heals and defensive cooldowns. Avoiding it is quite simple as long as you stay consistent. When he casts Bananarang, take a couple steps to the left or to the right, and the Bananarang will harmlessly pass by you on both its trip out and its return trip. Bananarang cannot be interrupted by standard interrupt spells, but CC effects such as stuns and blinds can break the cast. However, it is not worth using these spells on Bananarang because The Yowler will just cast it again after the effect wears off. It won’t stop him from using it; he will spam it until he gets the ability off.
Going Bananas can often be his most devastating ability, but sometimes it repeatedly misses you entirely. As soon as his cast for Going Bananas finishes, he starts a channeled version of it. There are three main ways to deal with this ability. The first is to use CC effects (stun, blind, knock down, punts, and possibly others) to break the CHANNELED ability. If you use the CC while he is casting it, he will just immediately cast it again (same as Bananarang and Toss Filth). While interrupting with a CC is the easiest way, it is also highly class-specific, so I’ll also highlight two other ways to deal with Going Bananas. The second way is to use the environment to your advantage. Hozen rares almost always spawn in caves or cramped areas, and when they’re jumping around and Going Bananas, they will almost never be able to leave the cramped area they are in (unless you pulled them outside). Therefore, you can just fight the Hozen in the cave and then run outside the cave entrance when he starts Going Bananas. The final way is the most random and most difficult – just simply try to dodge it. You have around one second to dodge him when he targets the ground and you can try to anticipate his moves and work around him. Alternatively, you can just try to dodge by staying exactly where you were when Going Bananas started; this often works because the Hozen will try to attack everywhere around that spot but usually not that spot directly.
Like all Pandarian rares, The Yowler's respawn time is usually one hour. However, sometimes only six or seven out of the eight rares will respawn at once, instead of all of them at once. The rares do not respawn with the rest can sometimes skip a cycle, matching the next respawn of all the rares in the zone, or even just be delayed by 15-30 minutes.
The best way to get a specific rare is to check periodically to see if any rare in the zone you want is dead or alive. If it is alive, go quickly check the specific rare in that zone to see if he is up and if he is, enjoy! If any rare in the zone is dead, come back in approximately 50-55 minutes and hang out near your rare’s respawn. Most of the time, you will catch it in the act of respawning and are assured to be the first person to get a shot at the kill!