Creating Sprite Files

Firstly you can use any drawing package to make bitmaps, I personally recommend Paint Shop Pro 7 for its range of tools and ease of use.
The best thing about this particular version is that it is abandonware.

Download this bitmap which has the correct palette for Creatures, and open it in your chosen image editor.

Then copy the image from the package to the palette bitmap and save it in 24 bit bitmap format.

You might get distortion due to the limitation of the palette, if you do adjust your original image then re-copy it to the palette bitmap.

Please note that true black is interpreted by the game as invisible.
So if you want part of your sprite to appear dark, then you must use one of the near-black colours.
Certain shades of white appear in the game as black, so you may have to experiment a little.

Make sure the width of the image is a multiple of 8,
using the attributes option in the Image menu.
Otherwise it will become distorted when used in the game.

Background sprite tile sets must be 144 pixels wide and 150 tall
The world must be exactly 58 tiles in width, 8 in height.

If you want multiple images in one sprite, it is very useful to number them with the same name after the number, and use leading zeros.
For example:
 
00cabbage, 01cabbage, 02cabbage, 03cabbage

 Various sprite compilers will automatically put them in order if you name them this way, saving a lot of effort in the long run.

Now open Creatures Editor,select "Compile SPR File"  from the "Sprite Manipulator" sub menu.
Now locate and select the files you wish to include in the file. Note that you are best selecting the last in a series then the first one when highlighting a series or the program will rearrange the files.

Alternatively you can use One Sprite Worksop or Sprite Builder by Cyberlife, or this online one by Bedalton.

You can now create your file - remember to give it a unique four digit name, preferably one that is not of the name structure used by the Creature Sprites, to leave space for creatures!

Remember to copy or move the new file to the /Creatures/images directory, or the game code cannot access it.

You can now create a cob to inject this sprite into your world.