Here is the full list of all 39 Blacksad: Under the Skin achievements.
Watch all 6 alternate scenes at the end of the game.
Complete the Hall of Fame album.
Complete the Hockey sheet of the Hall of Fame album.
Complete the Baseball sheet of the Hall of Fame album.
Get hired twice for the same case.
Complete the Football sheet of the Hall of Fame album.
Contribute to as many deaths as possible.
Stand up to Sam as many times as you can.
Complete the Boxing sheet of the Hall of Fame album.
Find all false endings in the game.
Take 400 nightstick blows. Maybe a few less.
Do not take the case.
Help the Colberts live a second honeymoon and receive their gratitude.
Interact with as many books as you can.
Stand up to Quince as many times as you can.
Complete Blacksad's silence conveniently.
Complete the game without dying a single time.
Complete the game dying less than 9 times.
Now for real.
Complete all deductions in the game.
Solve the case.
Take your sixth beating.
Do not scare Brunhilda while telling her a story.
Beat someone up for once.
Play baseball.
Play bad cop convincingly.
Play good cop convincingly.
Take your fifth beating.
Why's that poster in Dunn's flat?
Put your acting skills to the test.
Charm Helen Moore into giving you a present.
Take your fourth beating.
Buy a box of cigarettes from the nursing staff.
Take your third beating.
Take a ride with the city's most honest bookmarker.
Buy your favorite goat a second burger.
Take your second beating.
Find your most valuable tool.
Take your first beating (spoiler: it won't be the last!).