Pilot episode

I grew up in the 90s and saw a lot of Cartoon Network's shows as pilots on the What A Cartoon Show. I can't find any evidence of this, but I swear I remember seeing the first episode of Billy & Mandy, Meet The Reaper, years before it became a full series.

Is my memory playing tricks on me? I very distinctly remember seeing it in the 90s. Can anyone concur? What was the original air date of the episode?