4-B4 was a droid. It accompanied Jedi Master Dajjun, his Padawan Karii, and a number of other Jedi on a mission to the planet Kailion. It was caught with the Jedi when they were trapped in a cave-in.
Behind the scenes
The miniature used to represent 4-B4 in this scenario is a ASP-7 droid; however, it is not clear whether this is intended to be 4-B4's actual model.
Sources
Peril in the Kailion Caves on Wizards.com (backup link) (original site is defunct)
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