There are 6 unique codex entries in the Bestiary section on Tython. 2 are accessible to all players regardless of class or faction and 4 are faction specific.
Guid is obtained from killing a Greater Guid. It can also be obtained from killing Foraging Guid, The Crystal Eater, Trapped Guid, and Bouldersmasher on Ilum or Trapped Guid in Relentless Replication.
Codex type: Bestiary | Faction: Republic | Class: All
Associated Achievement: Beastmaster of Tython
Horranth is obtained from killing a Horranth Matriarch.
Codex type: Bestiary | Faction: Republic | Class: All
Associated Achievement: Beastmaster of Tython
NAME is obtained from speaking with Bahlea during "Pilgrim Medicine" mission.
Codex type: Bestiary | Faction: Both | Class: All
Associated Achievement: None
Tythonian War Droid is obtained from killing a Tythonian Seeker.
Codex type: Bestiary | Faction: Republic | Class: All
Associated Achievement: Beastmaster of Tython
Uxibeast is obtained near a proximity map trigger.
Codex type: Bestiary | Faction: Republic | Class: All
Associated Achievement: Beastmaster of Tython
Wingmaw is obtained from killing a Wingmaw Bonecleaner. It can also be obtained from killing Wingmaw Flayer on Tython.
Codex type: Bestiary | Faction: Republic | Class: All
Associated Achievement: Beastmaster of Tython