Here is the full list of all 39 Blacksad: Under the Skin achievements.
Complete the Baseball sheet of the Hall of Fame album.
Complete the Hall of Fame album.
Watch all 6 alternate scenes at the end of the game.
Contribute to as many deaths as possible.
Complete the Football sheet of the Hall of Fame album.
Complete the Hockey sheet of the Hall of Fame album.
Complete the Boxing sheet of the Hall of Fame album.
Play bad cop convincingly.
Find all false endings in the game.
Buy your favorite goat a second burger.
Stand up to Sam as many times as you can.
Do not take the case.
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.
Complete Blacksad's silence conveniently.
Play good cop convincingly.
Take your fifth beating.
Interact with as many books as you can.
Why's that poster in Dunn's flat?
Take your first beating (spoiler: it won't be the last!).
Find your most valuable tool.
Take your second beating.
Take a ride with the city's most honest bookmarker.
Take your third beating.
Get hired twice for the same case.
Take your fourth beating.
Put your acting skills to the test.
Take 400 nightstick blows. Maybe a few less.
Charm Helen Moore into giving you a present.
Stand up to Quince as many times as you can.
Help the Colberts live a second honeymoon and receive their gratitude.
Buy a box of cigarettes from the nursing staff.