Not quite what you asked for ...
DEXTERITY
Jermalaine
-8 Str, +6 Dex, -2 Con, -2 Int, +6 Wis, -4 Cha (+0 LA). (thanks Orient)
Wendigo Lesser Aasimar
Str +4, Dex +6, Con +4, Wis +4, Cha +6 (+4 LA).(thanks Orient)
catfolk
+4 dex, +2 cha and 40 ft speed for +1 LA (races of the wild)
Petal
Str -6; Dex +10; Con +4; Int +4; Wis +0; Cha +8 (LA +2, HD=0) - also has DR, flight, and tiny size (cohort only)(MM III)(thanks fawr)
Petal 1/2 Golem Incarnate construct
Str +6; Dex +8; Int -2; Wis +0; Cha +2 (Worse stat wise than a petal but no LA and playable) - also has DR, flight, and tiny size (MM III)
Wererat Githzerai
+12 Dex, +2 Con, +2Wis, -2 Int, +4LA. (Thanks Rilem)