After looking into the heart of the TARDIS, the Time Vortex itself filled Rose Tyler, who then temporarily became the Bad Wolf entity. She scattered the two words throughout time as a sign to herself that she was linked to the Doctor, creating a looped ontological paradox. Read more at https://tardis.fandom.com/wiki/Bad_Wolf_(entity)
About The "Bad Wolf Vinyl Sticker" From The Geek Leak
Sticker Use: For car, window, laptop, etc...
Item Height: 7.6cm
Item Width: 17.8cm
Material Type: vinyl
Your sticker has 3 parts:
Paper Backing Sticker Clear Transfer Tape
1 Clean the surface where the decal will be applied.
2 Slowly removed the paper backing making sure that your decal remains stuck to the clear transfer tape. If part of your decal lifts up with the backing, press the paper backing back down against it until it stays stuck to the transfer tape.
3 Once your decal is peeled away from the backing, line up & position your decal against the surface to which it will be applied.
4 Use a credit card or something similar to smooth down your decal, making sure that it is completely stuck to the surface.
5 Carefully & slowly, remove the transfer tape from your decal, making sure that your decal is stuck to the surface. If you see part of the decal does not release from the transfer tape, press it back down to the surface and repeat the process.