Here is the full list of all 12 Undercat achievements.
Unlock the first Resistance base
Unlock the second Resistance base
Unlock the third Resistance base
Complete the game
Finish a PVP tournament for the first time
Collect every trophy
Shake 10 enemies
Shake 50 enemies
Shake 100 enemies
Mark 10 hydrants
Bark 20 times
Sniff 10 times