Avatar itself averts this, but provides a meta example (or Truth in Television). The human antagonists in the movie are depicted as considerably lesser bastards to aliens than their counterparts in District 9. They regard the Na'vi as primitive and hostile people, but people nevertheless: they at least try (if halfassedly) to resolve the conflict with diplomacy and trade and even when they resort to violence there are still some token efforts to reduce Na'vi casualties. On the other hand, the prevalence of "should've napalmed/nuked/asteroided them" attitude in reviews and on forums, assessments of Jack/Ney'tiri relations with heavy zoophiliac overtones and notes like "It's like trying to negotiate with cockroaches" suggest a view of the Na'vi as subhumans who should be exterminated.
Make My Monster Grow and One-Winged Angel are often invoked to get around this in children's shows. In addition, said creatures may be fairly articulate before the change but lose all vocal coherence after.