Here is the full list of all 27 Peregrin achievements.
Reach the final monolith
Activate the last totem in your journey
Discover all investigation points
Reach the fifth monolith
Complete the Chapter 5 plane flame puzzle first try
Reach the fourth monolith
Reach the third monolith
Kill an enemy using a sentry turret in Chapter 5
Possess a creature 100 times
Make your way across Chapter 3's crucibles with 15 or fewer button presses
Clear a battle zone using only a single heavy enemy
Possess every possible creature
Complete the Chapter 3 generator puzzle first try
Reach the second monolith
Give yourself the upper hand in Chapter 2's final battle
Complete Chapter 1 without dying
Reach the first monolith
Possess a creature 50 times
Use a light enemy to kill a ranged enemy
Spend 60 seconds on a single vista scene
Activate 20 totems
Activate 10 totems
Die 5 times
Activate 5 totems
Possess a creature 10 times
Force an enemy to kill their ally
Discover an investigation point