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