Not GP, but Gary Bernhardt is the guy who gave the classic "Wat" [0] and "Birth and Death of JavaScript" [1] talks, and some searching turns up "pretzel colon" as the "&:" operator in Ruby [2]. I assume he's mentioned it in a screencast or something, but I wasn't able to find it.

[0] https://www.destroyallsoftware.com/talks/wat

[1] https://www.destroyallsoftware.com/talks/the-birth-and-death...

[2] https://technology.customink.com/blog/2015/06/08/ruby-pretze...