Here is the full list of all 8 Fabular: Once Upon a Spacetime achievements.
Unlock the Manticore player ship
Defeat Dax the Deserter with the Paladin
Defeat Dax the Deserter with the Manticore
Defeat Warchief M'urdu with the Paladin
Defeat Warchief M'urdu with the Manticore
Defeat the Endkeep with the Paladin
Defeat the Endkeep with the Manticore
Complete Sir Lombardo's tutorial