Greg responds...

1) Brooklyn developed overtime. He began as two characters in the show's
original comedy development. "Amp" looked more like Lexington, but had
Brooklyn's basic personality. "Lassie" (a male gargoyle who admired the
collie's heroic qualities) was an idiot-savant character. But he looked a
bit like Brooklyn. I think Bob Kline did the original designs on these
comedy characters. (They were all diminutive.) Dave Schwartz redesigned
Brooklyn, Lex and Broadway. The final models were done by Kazuyoshi Takeuchi
based on Dave's inspirational design. Frank Paur also made some minor
changes to it.

2) One answer is because the character demanded it. That is the stories of
his life seemed to exist and need to be told. On another level, I felt that
childhood friendships must evolve or die. Brooklyn, Lex and Broadway
couldn't go through life as The Three Musketeers. By sending Brooklyn away
for five minutes of Broadway's life, but forty years of Brooklyn's it would
demonstrate that although the trio would always be the best of friends, the
days of being joined at the hip were quite, quite over.