I find the drawings of all very charming animals. There orangutan making an "O" with his body and his long arms or the lizard takes a nap on the belly, tail in the air to make the 'L'.
For children a little older, there is something to learn from texts that play with rhyme and alliteration.
My favorite text, it has to be Jaguar "! J like a jaguar perched on his perch, jubilant, thinking of the prey that will taste tonight"