"The Merchant of Menace" is the fifty-second episode of Darkwing Duck.
When Quackerware comes to life, S.H.U.S.H. thinks Herb Muddlefoot is behind it!! Drake investigates by joining in on Herb's Quackerware sales route. It turns out to be none other than a scoundrel named Lowly Weasel in disguise, trying to ruin Herb's reputation.
Darkwing: Yikes! Gryzlikoff! This looks like a job for... [ducks behind a tree and changes into his Darkwing attire] The terror that flaps in the night!
Gryzlikoff: Darkwing Duck! This is my case!