The ice toad (Frostburn 140-1) is a magical beast with an Intelligence score of 6 yet no language. Beyond being conceptually annoying and making me feel bad for the handful of aberrant genius ice ...
The Fiendish Codex I mentions Ahrimanes, the Chief of the Cacodaemons (p.155). But what exactly a Cacodaemon is goes unmentioned. They're mentioned in 4e, AD&D 1e and Pathfinder, but as far as I ...