Tales From The Cryptkeeper
Season 1, Episode 09
Hyde and Go Shriek
We interrupt the Cryptkeeper's workout--he's running on the dreadmill, of course--so he pauses long enough to whip up a healthy shake and a frightful story called Hyde And Go Shriek (which is twice the puns for the price of one).
Nice guy Wendall has been bullied by Rex and his hooligan pals for years, but when he finally has enough, he vows revenge against his tormentors. He tries to bulk up, but when it becomes obvious that it's going to take too long the old fashioned route, he looks for a shortcut in a box labeled Zen Master Tea.
He becomes a monster that looks more akin to a werewolf than Mr. Hyde, but the transformation is brought on by the "magic tea" rather than the phases of the moon. Strangely, this was possibly intended as a sly allegory about the dangers of steroid use, but making it an herbal tea really stopped the message in its tracks. If anything, it would scare the kids away from vitamins.
As someone who was tormented in their youth (looking a lot like Wendall, to be honest), I enjoy any story where the tables are turned on the bullies. After seeing this episode as a child, I probably had my mother rush out and buy every brand of herbal tea on the market.
If it worked, I blocked out the memories.
An amusing episode, although there was a sorely missed opportunity for a Monster Vs. Monster showdown at the finale.