When you think about it, dolphins are actually sort of scary.
Not only are they amongst the most intelligent of sea creatures, dolphins even have their own kind, cross-species cooperation in dolphins is quite common. There's been a huge number of anecdotal evidence about dolphins coming to the rescue of divers and vice-versa.
All that aside, they're also extremely friendly as this cute little video shows. It's just a little toddler and a dolphin playing catch in a swimming pool.
For his or her part, the dolphin really does seem to be enjoying himself and it's great to see the toddler having a ball (heh) as well.
Dolphins, man. They'll probably kill us all if they ever develop the ability to walk on land, but still.