waterproof clay for water birds

Does somebody nows where you can buy waterproof clay in holland becaus i want to make flamingo's and egrets that can stand in the water??

I think You want them in miniature scale not life size to garden?

For small scales I can recommend Super Sculpey, after baking it is waterproof. :) You can buy it through formx.nl .
For life size birds You would need to do more complicated technology

Thank you Ana but it is a littlebid expensive so is there some cheaper waterproof clay for making miniature birds?

I think Fimo is easier to get and sold in smaller packages, it's not cheaper when You count price/weight but per pack it is. :) It's very similar to Super Sculpey and You find it in most hobby shops :)