I'm looking for the shortest official humanoid creature I can transform into with the second level wizard spell alter self.
This excludes taking feats or archetypes to get even shorter, of course. Additional effects to get even smaller and incospicuous will be factored in later (reduce person, for instance).
I perfectly know being smaller doesn't actually make it easier to hide, unless your Size changes, this is just for roleplaying purposes.
Humanoids from 3.0 are ok as well but please note which one is the smallest viable in 3.5e anyway. Up to now, I found female kobolds to have a lower height limit of 2 feet (around 60 cm).
For alter self purposes, I'm a medium sized humanoid (human).