Nasty Net

From the Super Mario Wiki
Nasty Nets

Nasty Nets are special nets that can be launched from the Doomsub. Their only appearance was in The Adventures of Super Mario Bros. 3 episode "The Ugly Mermaid".

The main purpose of a Nasty Net is for catching and holding enemy targets, such as Luigi. Upon hitting its target, a Nasty Net will wrap itself around it entirely.

They are fairly durable, and do not conduct electricity, as Mario and Luigi managed to collect a school of Jelectros in one without getting shocked. While most characters are not strong enough to destroy a Nasty Net, a Chain Chomp can chew through them in a single bite.