Critter Stats
In general all critters (not creatures with class levels) in the SRD and MM have stats generated from the base statistics of 10 or 11 for each score and then applying racial modifiers. So, for example, the Worg has:
Str: 17 Dex 15 Con 15 Int 6 Wis 14 Cha 10
Subtract 11 from all odd scores and 10 from all even scores to get the racial modifiers:
Str +6 Dex +4 Con +4 Int -4 Wis +4 Cha +0
So, if you roll stats for your worg (with 4d6 drop the lowest, or whatever method you use) you should apply the above noted racial modifiers after rolling.
Note that for most humanoids critters with NPC class levels (goblin warrior, orc warrior, etc.) the critters were generated with the Nonelite Ability Score array: 13, 12, 11, 10, 9, 8 and then applying racial ability score modifiers.
Finally, critters with PC class levels have the Elite Ablility Score array: 15, 14, 13, 12, 10, 8 and then applying racial ability score modifiers.
Hope that helps.