What is a catfish amendment?

A seemingly friendly amendment designed to kill a bill by making it undesirable.

As an example, a legislator proposes a term limits bill. Another legislator, seeking to undermine it, suggests making them retroactive, knowing that would disqualify many sitting lawmakers from running again.

The term has been used in North Carolina politics at least since the 1950s. It likely originated with an old joke about a fisherman popular among Southern lawyers and politicians: "Hold still little catfish, all I'm gonna do is gut you."

The first known reference is from an April 17, 1957, article in The News & Observer.

After a committee amended a minimum-wage bill multiple times to exempt almost half of the state's workers, its chairman, Lumberton Democrat Sen. Cutlar Moore, compared the legislators to the fisherman in the joke.

The etymology was explored in depth here, here, here, here, here, here, here and here. For an example of a "catfish amendment," see here.