https://en.wikipedia.org/wiki/Cow_tools

I assume you are just asking for clarification about the Far Side part of this, but for anyone who does not understand the It’s Always Sunny in Philadelphia part:

In a memorable scene from S7E13 “The High School Reunion Part 2: The Gang’s Revenge”, Dennis grabs duct tape, zip ties, and other suspicious items and shouts “Tools! I have to have my tools!”

https://www.youtube.com/watch?v=ype12RuDJ4k