Interpretations:I Found A New Friend Underneath My Pillow
Perhaps the new friend under his pillow is himself. Perhaps he is hiding under his pillow becuase he has no friends. So he finds himself while under his pillow and he is his own new friend.
There's a wedding ritual people forget about where any single woman attending would bring home a piece of the cake and sleep on it, placing it underneath her pillow. Doing this is supposed to let her dream of her own future wedding, and catch an image of her future spouse.
The toothfairy may be a new friend also, but you won't get to see her.
I think it's just supposed to be funny. ~AgentChronon