XKCD is a popular webcomic allegedly written by Randall Munroe, and is very popular among programmers, and those in Repl.it included.

XKCD's art style is simple, even for comics, with all characters being stick figures, which leads to the logical conclusion that Randall Munroe is spreading pro-tree propoganda, and also explains how the webcomic is able to make money (donations from the Tree Deep State). This theory has been confirmed after the appearance of trees in multiple comics.