Here is the full list of all 25 Creature in the Well achievements.
Heal a total of 1,000 health absorbed from anomaly balls
Find all capes
Find all the lore
Help Roger mop the floor
Find Phillip's prototype
Fully upgrade the BOT-Core
Save Mirage from the sandstorm
Find all of Danielle's tools
Enter the Creature's well
Find the scavenger's hidden stash
Unlock the Weather Control Monolith
Generate a total of 2,000,000 power
Destroy 100 drones using EMPs
Unlock the Support Monoliths
Charge 7 orbs at once
Try to escape the sandstorm
Upgrade your BOT-Core
Let's play
Get thrown out of the machine
Find a secret strike tool
Hit 20 bumpers with one shot
Activate the Power Reserves
Find a secret charge tool
Generate 1,000 power in one hit
Open the temple