Koopascope

From the Super Mario Wiki

The Koopascope is a special parascope-type device that was created by Kooky von Koopa, which was used to see through Warp Pipes.

In The Adventures of Super Mario Bros. 3 episode "Oh, Brother!", Kooky used the Koopascope to spy on Mario and Luigi in the Mushroom Kingdom from an underground dungeon. By simply inserting the Koopascope into a Warp Pipe, Kooky was able to monitor Mario and Luigi on the other end of a network of pipes.

The Koopascope was clearly designed for capturing purposes, as one can view their target through the Koopascope with crosshairs.

Kooky von Koopa's Inventions
Doomship | Koopa Klogger | Koopascope | Kooper-Dooper Raiser-Upper | Lame Brainer | Mega Mechanasaur | Nice Guy Potion | Plumber Pole | Power Pendant | Power Shower | Robot Princess | Super Slurp Pipe | Time Travel Tube