Note: Shifted Lines
Siala reported on Discord that they were experiencing missing heads and arms from the vanilla assets after merging in some Custom Content head models. Siala found that the issue was caused by shifted columns in Appearance.2da. IF you experience this issue, this might be a good place to start troubleshooting.
Note, I have found Excimer's 2DA Combinulator and TextPad to be flawless tools for merging or working with 2DA files.

Adding a new model appearance for a creature? Recommendation is to copy an existing line and tweak if the model author didn't supply one.
| Column | Example Contents | Valid Values | Description and Notes |
|---|---|---|---|
| LABEL | Badger_Dire | Any string | Unused by the game. Used in the toolset if the STRING_REF column is blank |
| STRING_REF | 1994 | A dialog.tlk string refrence | Used by the toolset to show what the name of the appearance is, if blank then LABEL is used. Unused in game itself. |
| NAME | Badger | Any string | Unused by the game or toolset for humans only. |
| RACE | |||
| ENVMAP | default | Named environment map file. The filename without .tga at the end. default evmap_irrid evmap_azer | Note: This is ignored if a TXI file is used by the given model. default can be used to add some additional "shiny" to metals and other materials on creatures if they don't have it already For custom ones see Environment Maps and Cubemaps for some further information. Some examples are in the column to the left and can be extracted from the game bifs. If blanked (****) then no environment map will be used. |
BLOODCOLR | G | "G" (green), "N" (none), "R" (red), "W" (white), and "Y" (yellow) | |
| MODELTYPE | |||
| WEAPONSCAPE | |||
| WING_TAIL_SCALE | |||
| HELMET_SCALE_M | |||
| HELMET_SCALE_F | |||
| MOVERATE | |||
| WALKDIST | |||
| RUNDIST | |||
| PERSPACE | |||
| CREPERSPACE | |||
| HEIGHT | |||
| HITDIST | |||
| PREFATCKDIST | |||
| TARGETHEIGHT | |||
| ABORTONPARRY | |||
| RACIALTYPE | |||
| HASLEGS | |||
| HASARMS | |||
| PORTRAIT | |||
| SIZECATEGORY | |||
| PERCEPTIONDIST | |||
| FOOTSTEPTYPE | |||
| SOUNDAPPTYPE | |||
| HEADTRACK | |||
| HEAD_ARC_H | |||
| HEAD_ARC_V | |||
| HEAD_NAME | |||
| BODY_BAG | |||
| TARGETABLE |