Banshee - Main character.
The bat - Just talk to him at the entrance f the mines for an easy party member.
The chicken - Kill all the wolves at the farm and recruit him at the chicken coop.
The butterfly - At the blacksmith tower, on the spike floor go south instead of north, then head up the southern stairs and you will encounter a miniboss. Make it past that miniboss and then up the stairs to recruit the butterfly.
I think that's all might be false though.