Smiling Tiger. The whole article may be read here. Enjoy!
There are two versions of how Dong learned Baguazhang. The first version tells how he got lost in the regions south of the Long River. He was looking for some old friends on Jiuhua mountain but became lost among the peaks. There were no tracks to follow and he couldn't find the trail. As hunger and exhaustion mounted, he thought he would surely die. But just as his anxiety seemed to peak, suddenly there appeared a man who lead Dong to see an old Daoist priest. This Daoist had white downy hair, yet the complexion of a child. Dong watched as the old man practiced. His steps were like floating clouds and flowing water. His palms turned and changed as swift as the wind and as quick as lightning. Dong begged to be taken on as a student and the old Daoist allowed him to stay in his temple. For two years Dong did nothing but walk a circle around a tree until his stepping had carved a trench a foot deep. Then the old Daoist taught him the Single Change Palm. When Dong had mastered everything his master had to teach, he was getting ready to leave. The Old Daoist said to him, "Eventually you must return home. However, when a difficult situation arises, remember my teachings!"
A second version tells how Dong traveled to Emei Mountain in Sichuan. There he met a man named Dong Menglin who taught him Yin Yang Ba Pan Zhang. Dong altered what he had been taught and changed the name to Baguazhang.