EIEIO

For certain animals, when Elliot sees them, the chorus of Old MacDonald had a Farm appears from Elliot's lips. Most of the animals which bring this chorus about are indeed farm animals but there are times when Elliot sings EIEIO when seeing Elephants or Giraffes or Zebras.
With his mother, Elliot has learned to identify many animals and their sounds. When we ask what a horse says, Elliot will say "nay". When we ask Elliot what a cow says, Elliot will say "moo". He knows that chickens say "cluck" and his favourite now is cats which say "mao" or are maoists, depending on how you interpret Elliot's language.
He identifies animals when he sees them or pictures of them and he identifies them when he hears them too.
Elliot and his mom go to the zoo when they get the chance. Elliot enjoys that a lot.