There are 6 unique codex entries in the Bestiary section on Dromund Kaas. 5 are accessible to all players regardless of class or faction and 1 is class specific.
Akure, the Ghost in the Darkness (Bounty Hunter) is obtained from killing Akure, Ghost in the Darkness during "The Heart of Darkness" mission.
Codex type: Bestiary | Faction: Imperial | Class: Bounty Hunter
Associated Achievement: None
Gundark is obtained from killing a Gundark Lifetaker.
Codex type: Bestiary | Faction: Both | Class: All
Associated Achievement: Beastmaster of Dromund Kaas
Jurgoran is obtained from killing Howler.
Codex type: Bestiary | Faction: Both | Class: All
Associated Achievement: Beastmaster of Dromund Kaas
Sleen is obtained from killing a Lethargic Sleen.
Codex type: Bestiary | Faction: Both | Class: All
Associated Achievement: Beastmaster of Dromund Kaas
Vine Cat is obtained from killing a Savage Vine Cat. It can also be obtained from killing Sharpclaw on Dromund Kaas.
Codex type: Bestiary | Faction: Both | Class: All
Associated Achievement: Beastmaster of Dromund Kaas
Yozusk is obtained from killing Yozusk Platesmasher.
Codex type: Bestiary | Faction: Both | Class: All
Associated Achievement: Beastmaster of Dromund Kaas