To replace your character model in the game, while playing:
Enter command prompt mode by pressing the '~' key
Type in 'DebugMode 1' and hit <Enter>
Enter command prompt mode again by pressing the '~' key
Type in 'SetAppearance #', where # is the number of the desired model (between 1 and 298), and confirm it by pressing <Enter>
Note: all commands are case sensitive.
RealmForge over at the BioWare forums was kind enough and patient enough to detail available models:
Model #
Model Name
8
Badger
9
Dire Badger
10
Bat
12-15
Bear series
17-20
Beetle series
21
Boar
22
Dire Boar
24
Bone Golem
25-30
Bugbear series
31
Chicken
34
Cow
35
Deer
37
White Stag
38
Balor
39
Lich
40
Doom Knight
41-50
Dragon series
51
Dryad
52-53
Air Elemental
54
Intellect Devourer
55
Pixie
56-57
Earth Elemental
58-59
Mummies
60-61
Fire Elemental
62-63
Skeletal Warriors
64
Shadow
68-69
Water Elementals
70-71
Skeletons
72
Flesh Golem
73
Gargoyle
78-81
Giant series
82-87
Goblin series
88-92
Golem series
93-95
Big Cat series
96
Dire Wolf
97-98
More Big Cats
99
Rakshasa
101-102
Aberrations
103
Will O' Wisp
104-115
Imps and Mephits
119-122
Minotaur series
123
Morhg
124-125
More Mummies
126
Nymph
127-129
Ogre series
130-135
Lizardfolk series
136-141
Orc series
142
Ox
144
Falcon
145
Hawk
146-147
Shades
148-150
Skeleton Lords
151-155
Slaad series
156
Spectre
157-162
Spider series
163
Succubus
164-167
Troll series
168
Umber Hulk
170
Wererat
171
Werewolf
172
Wight
174-181
Canine series
182
Skeletal Champion
184-185
Wolves
186-187
Wraith
189-190
Aribeth
191-192
More Lizardfolk
195-199
Zombie series
200-201
Archery Targets
202
Panther
203
Cougar
204
Bear
205
Gray Render
206
Penguin
207-209
More Ogres
215-216
Drow series
239
Old Man
240
Old Woman
241
Boy
242
Girl
290
Rakshasa Female
293
Rakshasa Male
294-295
Archons
298
Invisible
The keen-eyed amongst you may note that not all numbers are represented in this list. The missing numbers are generally humanoid models that can be created by customizing armor and clothing, without changing models.
If you discover any errors in this list or have information to add, please contact us.