Seel, Omanyte, Kingler, Pelliper, Gastrodon(West sea), Tentacool, dewgong, staryu, dragonair, Walrein.
The bosses at the end are Kabotops and two Omastar.
I haven't seen azurill in Pokemon Mystery dungeon explorers of time a lot. I gues you could find azurill in one of the water related dungeons. (Example: Waterfall Cave, Brine Cave, etc.)
buy them or go on the missions and get them as a reward Also find them at brine cave, mystifing forest or apple woods sometimes have a few. I recommend brine cave it helped me dfeat Dialga.
In Pokemon Mystery Dungeon: Explorers of Darkness, the TM for Shadow Ball can be found on B1F of Brine Cave after reaching the Gold Rank. It is located inside a locked room and requires a key to access.
In Pokémon Mysery Dungeon: Blue Rescue Team, you can find the Poison-type Pokémon that is named Ekans in the dungeon that is called the Western Cave and you will be able to locate it on Floor 3, Floor 4 and Floor 5.
Bullet Seed can be found in the southern part of the Brine Cave dungeon, in Pokemon Mystery Dungeon: Explorers of Time. It is located on floor B11-B14 and can be obtained by defeating the Pokemon holding it.
There is 1 Kabutops and 2 Omastar =]
See related link.
brine cave
A dungeon is a cave on pokemon mystery dungeon. It is a level with a series of floors/rooms and the object is to get to the end of the dungeon.
There are 19 floors in the Landslide Cave dungeon in Pokemon Mystery Dungeon: Explorers of Darkness. The dungeon is known for its rocky terrain and challenging battles with ground-type Pokemon.
Mewtwo lives in cryptic cave, you can get Cryptic cave from wigglytuff in the Pokemon square.
In Aegis Cave