Bestial Intellect (3.5e Flaw)
From D&D Wiki
You’re just a dumb beast.
Prerequisite: Cannot be Mindless.
Effect: You automatically fail knowledge checks and cannot gain any ranks in Knowledge skills or speak language. You only know how to perform certain actions as listed in the Alter Program ability of the Bot Subtype except the mimic action is not an option, use handle animal instead of program, and automatically know how to use any special abilities due to race or class and well as self-preservation and identify creature and identify object.
Special: Detect thoughts and mindreading effects only register you as an animal. Speak with animal’s enables communication as if you were an animal.