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 Windows-1252 encoding with support for accented characters common to European languages.
The file format is as follows:
|char||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)|
|u16le.||Actual width of character at this index. Character data is left-aligned.|
|...||Additional character widths.|
There is a Japanese font for Creatures, which includes katakana in addition to the normal ASCII characters (and maps to the Windows-932 encoding internally). Each character's data is 11 pixels wide to accommodate the larger Japanese characters, increasing the character data size from 72 bytes to 132 bytes.
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)|