Java Edition:Ender Dragon in Boat
From 15w41a - 15w47c (1.9 snapshots) the ender dragon could enter a boat. In 15w49a this glitch was removed.[1]
Obtaining
You can get the Ender dragon in the boat anywhere during flight, but from the exit end portal is the easiest. Since you know she will come to that pedestal periodically, you can put the boat on top of the bedrock pillar of that portal. Once the Ender dragon is in the boat, the player cannot enter the boat because her hit box is many times larger. However, the player can be in the boat when the Ender dragon enters. This will allow the player to steer the ender dragon around, but also take lots of damage. It's possible, though, to stay alive with healing, such as enchanted golden apples and diamond armor enchanted with Protection IV. The player can also get multiple Ender dragons in boats by getting multiple ender dragons. The ender dragon can be in oak, spruce, birch, jungle, acacia, and dark oak boats.