If you have 3D modelling software and some experience, you could create your own and use 3DXchange to bring the model into iClone. Alternatively, if you just want a talking Guinea Pig then you could take a good quality photo and animate it in Crazytalk 6 instead.
Alternatively you could bring in a pre-made prop model into iClone3 via 3DXchange like the one linked below. This would provide you with a standard prop without all the effort.
http://www.contentparadise.com/productdetails.aspx?id=134.
Peter EdwardsForum Moderator
iClone Daily Blog