Abhiṇha Jātaka (No.27)
The story of a dog and an elephant who grew up to be great friends and became indispensable to each other. The dog used to amuse himself by swinging backwards and forwards on the elephant’s trunk. One day the merchant sold the dog. The elephant went off his food and would not be consoled until the dog was brought back.
The story was told in reference to two monks of Sāvatthi who were very intimate with one another and spent all their time together. J.i.189 f.