Decals! For the wall, the car, the water bottle, where ever you may  need a hissing rat.

They measure about 3 inches at the largest dimension. If you want a smaller  or larger size, let me know! I can do that :)
These are available in black or white and in removable* or permanent**
They do take a little work to put onto your item. You will need a burnisher, (like a credit card).

For best results, apply your decal to a clean, smooth, and dry surface. Avoid textured or rough surfaces. Before applying, clean the area with rubbing alcohol and let dry thoroughly. After application, hand wash items gently - avoid dishwashers and harsh scrubbing to preserve your decal’s longevity.
These decals can be applied to any hard, smooth surface (car windows, laptops, metal or plastic water bottles, etc.). These vinyl decals will NOT stick to surfaces that are highly textured, porous, or rubberized. This implies they will not stick to things like fabric, stone or brick, or rubber mats as they have not been designed to adhere to these surfaces.er mats as it has not been designed to adhere to these surfaces.
 
*Great for interior walls, can be taken off, but not repositioned.
**Not actually permanent, but they will last for years on your car or laptop.