That episode was on today on TVLand and it made for some really funny moments and they could have used those kind of laughs for other episodes so did they ever have the Serena character on other episodes?

If they didn't that's a waste. They could've used more Serena and Sam episodes instead of some of the bad episodes.

Of course you all know that Serena is just Elizabeth Montgomery's portrayal of her twin cousin. Wouldn't it have been better if it was her twin sister since twin cousins are extremely rare if not unheard of.