This is the new amount of enemies to kill after the Advance Gungeons & Draguns update. I will list where to find and tips on to find said enemy.
Bullet Kin 200 - These enemies are the standard bullet enemies you encounter. You can find this enemy throughout the whole game. This is a quick challenge after a couple of runs
Blobulon 60 - These enemies are all the slime like enemies. These will only count if they are the big forms. These can also be found throughout the whole gungeon.
Hollowpoint 40 - These are the ghost enemies with machine guns. They can be generally found throughout the whole gungeon, but more commonly found in the earlier chambers of the gungeon
Gunjurer 40 - These little fellows are all the enemies that look like tiny magicians. They all have cloaks on and will all count towards the kill count. All these variations of enemies can be found throughout the whole gungeon.
Beholster 3 - This a 2nd chamber boss. You have a 1/3 chance to fight him. This boss is a red floating eyeball holding a handful of guns. Not a hard boss once you find the pattern to him. Easier if you have unlocked Boss Rush Mode for a guarantee fight with him.
Mimic 3 - Mimics are chests that are actually monsters. Thankfully you only have to find 3 of them. If you have already completed a "Past" with a gungeoneer, once you enter the 1st chamber, there will be an alter that will increase your curse to lvl 9 which will make finding Mimics much easier.
Gun Nut 25 - There are 3 types of these enemies, The Gun Nut, a brown big boy with a large red sword who can be found almost every time in chamber 1 and throughout the whole gungeon. The Spectral Gun nut, looks like a blue floating gun nut that can be found in chamber 5 and 6. And the Chain Gunner, a silver armor guy that pulls out a flail and swings it around and that can also be found throughout the whole gungeon.
Bullet Shark 35 - This enemies is a bullet that looks like a shark, fins and all. There are 2 variations, one being small and the other being hella big. The smaller can be found in chamber 2 and 3 and the bigger can be found in chamber 5 and 6.
Lead Maiden 25 - The lead maidens are the torture looking devices that open up and spray bullets in all directions. These enemies can be found in chamber 2, 5, and 6. Also can be found regularly in the Resourceful rat chamber.
Gunzookie 30 - These enemies look like little dinosaurs from the game bubble bobble. There is a green and pink one. They can be found in Chamber 2 - 4. In chamber 3, there is a room with 2 floating laser enemies that you have to dodge roll over pits. After you kill those two, it will always guarantee 2 bullet kins and 2 gunzookies.
Shambling Round 20 - These enemies are the totem pole looking dudes. These enemies can only be found rarely in chambers 3 and 6. Quick way is to use the elevator short cut to chamber 3 and go through the whole chamber and exit to breach then repeat.
Shelleton 20 - These look like golden skeletons. They can be summoned by the black coated, crown wearing enemy called Ammomancers. If you made it this far into the hunting quests, I am sure you know what I am talking about. If you only kill the shelleton they summon, they will summon up to 3 total. These can be found from chamber 3 - 6 and the Resourceful Rats lair. In the Rats lair, I have ran into 2 in a room quite constantly.
Shroomer 30 - These are a type of bullet kins that look like they exploded their head. When they shoot, they shot 2 bullets in a V, so if you stand still....they can not hit you. They can be easily found in the Oubliette. Also can be found in chamber 3 and 6.
Kill Pillars 3 - This is a boss in chamber 4. You have a 1/3 chance to fight them. They are 4 pillars being possessed by ghosts. These guys, in my opinion, is the easiest chamber 4 boss, especially if your using the Bullet character and the Blasphemy. You can also use Boss rush mode to guarantee a fight against them.
Dragun 5 - This is the Chamber 5 "final boss". The Dragon looking boss and the only Chamber 5 boss. I do not know if the advance form of this boss counts...but I do not see why it would not. Is an easy fight if you can find the pattern and blank when he starts to pull out the knives he throws on the walls to cancel them out. Again, Boss rush mode is the easiest way to get to him or skip to chamber 5.