Cory Belote has created Klingon-themed character sheets. Unfortunately, they are difficult to make form-fillable, but you can still print them out and fill them in. Alternatively, if you have Adobe Acrobat or can write over an image, you can insert text that way as well.
The following are image files (transparent, white background, and black background).
These are in A4. If you prefer letter-size, you can use ‘fit to size’ or otherwise scale it to print.