For a period that begun in September 1997 all the way until the relaunch of Toonami in April 2004, Williams Street-made show openings replaced original show openings for nearly all shows on the block. The very first custom show opening was for, of course, the very first show on the block, ThunderCats. Not that there was anything wrong with the custom openings as they were very fun to watch. Plus, it gave my brothers at Toonami Digital Arsenal a full-time job for the masses. But the original reasoning for the creation of the custom openings were a bit suspect. One high-profile Toonami producer originally stated that the reason for the custom openings is because we've seen the older openings over and over and over, and they wanted to give the viewers something interesting to watch.

In 1998, the first Toonami show to not show its original opening, Robotech, premiered, with a techno backdrop and a myriad of scenes that became a trademark of the block for years to come. While Toonami grew over the years, the original reason for the custom openings became null and void as the block began airing shows never seen on mainstream broadcast or cable outlets such as Gundam Wing, Tenchi Muyo, Dragon Ball, Outlaw Star, and countless others. Also, Toonami never explained why The Real Adventures of Jonny Quest was the only show intact after the custom openings began. Only a year after Toonami made a permanent move to Saturday nights did the custom openings go away permanently.

Yes, some of the custom openings were fun to watch, even better than the American openings at times. However, at the time of their introduction, they weren't warmly welcomed, so I'll call this the worst moment for the block.