CHARSET.DTA is the font used in Creatures 1 and Creatures 2. It contains 128 characters, matching the standard ASCII text encoding. Creatures 2 additionally has EuroCharset.dta, which contains 256 characters, matching the CP-1252 encoding with support for accented characters common to European languages.
The file format is as follows:
|72 bytes||Data for a single character - 6 pixels wide, 12 pixels high. It's not clear how pixels are mapped to colors.|
|...||Additional characters (128 total in CHARSET.DTA, 256 total in EuroCharset.dta)|
|16-bit integer||Width when rendered of character at this index. Character data is left-aligned.|
|...||Additional character widths when rendered|
There is a Japanese font for Creatures, which includes katakana in addition to the normal ASCII characters (and uses CP-932 encoding internally). Each character's data is 12 pixels wide to accommodate the larger Japanese characters.
It was hypothesized that there existed a Japanese font for Creatures 2, but the game is believed to never have been released for the Japanese market.
Prototypes prior to Creatures 1 used a different format. CHARSET.DTA contained the same 128 characters, but each was 4 pixels wide and 32 pixels high. Character width information was not included as all characters simply rendered as 4 pixels wide.
|32 bytes||Data for a single character - 4 pixels wide, 8 pixels high.|
|...||Additional characters (128 total)|