Here is the full list of all 17 Sigi - there are A Fart for Melusina achievements.
Collect all SIGI's.
There she goes again.
Defeat Ivan Stinkup.
An apple a day...
Defeat Kolles Terrol.
Defeat the Steel Horse.
Kill 100 Zombies.
Collect 1000 coins.
Defeat Blind John
Fart at Melusina.
Clear all caves.
Find the long lost golden grail.
Find the long lost golden crown.
Find the long lost golden talisman.
Hard to find and almost out of reach.
In under 30 minutes?
Pocket 2500 coins.