AP Nunu with Nashors Tooth?

Hi, I recently found out, that Nunu is a great lane bully in top lane, because of his poke and heal. But later in the game he falls off, because he has only one reliable damage ability. I think Nashors tooth could fix this problem. Compared with Morellos/Athenes it gives Nunu a second strong damage source (Autoattacks). If he consumes a monster of a outer camp or epic monster, he even has a on hit effect in his kit. On the other hand the advantage of Morellos/Athenes is mana regen, but Nunus passive gives him a mana-free ability after five autoattacks. With Nashors Tooth he can do more autoattacks, and therefore use more abilitys without mana costs. So Nashors tooth seems straight better than Morellos/Athenes. Has somebody tried this?