I've used bleach in the past for various crafty projects. As long as you are always careful when using it, it can be a great and cheap tool to use, but can take a bit of trial and error to get the desired results. This is the first time I've ever used bleach to stamp with and I think it was a great success.
To make this fox stamp get a small block of wood - you could use some layers of cardboard stacked together. Draw the design you want and copy onto a piece of craft foam. Once cut out, stick onto your block with Pva glue. Once your stamp is dry it's ready to use. get about an egg cup full of bleach and a brush. Gently paint the bleach onto the stamp, making sure you cover it evenly.
Print directly onto your chosen material (if it's a t-shirt remember to put a sheet of cardboard between the layers). I got about 3 fox prints to each bleach application but you can experiment and see what works best for you. Have fun (safely) bleaching!