katzin it depends on the licence of the art, if he didn't create it himself.
samblack can you prove that? I've done a bit of Googling there and can't find anything matching his art.
yes they are from google I found them many times:
__http://4.bp.blogspot.com/-nghN9Avj4s4/TkGPSB7UDjI/AAAAAAAAD6I/lN6ocr0r9HY/s400/Animalitos+vectorizados.jpeg
__http://www.imagenesydibujosparaimprimir.com/2011/08/pegatinas-animalitos-bebe-para-imprimir.html
but it doesn't mean he hasn't the propierties to use them there are many stock photos' sites with similar vector stock
for example:
__http://espanol.istockphoto.com/stock-illustration-21834861-vector-cute-safari-animals.php?st=8f34147