Cheap shops, like Poundland & B&M Bargains, do tubs of animals.
The Zoo set is useful for African stuff (Zebras, Lions, Giraffes etc)
while the Farm set gives some useful cows etc.
Take some small pins, bend them, cut off the heads & using a pair
of pliers push them into the cows head. When painted and multi-based
they should pass muster for a wargame.
Do not throw away the weird scale other animals. If you don't have any
children, who love these kind of things, convert them into alien beasts.
See my thread, 'Stuf Wot I Dun' where I simply cut the tails off over-scale
leopards & painted them bright blue. Players in one of my Sci-Fi games had
great fun shooting them, until I told them they had landed in a rare species
sanctuary & the (heavily armed) game wardens were about to arrive.
