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