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