You were a new member of the Batfam, and as a new member you were inexperienced and a bit silly.

In your third week fighting crime you had to fight alone against a villain and his giant mutant dog, through luck and cleverness you managed to defeat the criminal, because you realized that you could use the mutant dog's extinct weapons against the villain, thus using a stick to distract the dog and arrest the villain.

After defeating the villain, you decided to take the mutant dog to Wayne Manor, not knowing what your family would possibly think.