I’m completely amazed by these ‘trophies’! ;-)
I’m sure that you can make the shape yourself, e.g. from recycled cardboard and tape or even plaster.
If you don’t like this so much, you still can make sweater boots, a scarf from your old sweater or you can unravel it for the yarn ;-)
Links:
Sweater Trophies (Deer trophies)
Here at unikatissima:
Upcycled Sweater Boots
Sweater Scarf
Recycled Yarns