Pat Morita who played Arnold on "Happy Days" signed his contract pick-up option to continue for another 2 or 3 seasons, however soon after signing he was offered his own TV Series which developed into "Mr. T and Tina" which aired only 5 episodes.
There are another 5 episodes That have never aired as of January, 2015
The pilot episode underwent eight reshoots before finally being shown to critics who called it one of the worst shows ever.