Fully customizable ! If turtles are not your favorite thing, I'm always willing to try another animal. Color pattern can also be customized, but understand that some color patterns will make the font difficult to discern. 
'Standard' size for this item is 3.5 x 3.5 inches (like a Post-It note). It can be made larger, up to 11 x 11 inches. Significant size increase will affect the price.