La vaca que decia oink - Spanish reader by Bernard Most. Recommended in Lesson 8 - Las Pampas en Argentina - in the Sonrisas Cultural Curriculum.
There was once a cow who could only 'oink' and a pig who could only 'moo'--they were teased by all the other barnyard animals. A cow that went'oink'is made fun of by the other barnyard animals until she meets a pig that goes 'moo'. They team up and teach each other the 'proper' noise to make and end up having the last laugh because they're the only two animals that can say two noises. The sounds: 'moink' 'moo-in-k' 'moonk' make for a thoroughly fun way of learning that perseverance and a kind heart win in the end.
Paperback, 36 pages.