As far as I am aware less.pm is the only joke module in the Perl core.

The Perl source code and the venerable Configure script are littered with witty comments and Tolkien quotes, mostly courtesy of Larry Wall (see "Source code" and "Configure" sections at Larry Wall wikiquote). For example:

Parrot had a "Larry Wall/Dan Sugalski" easter egg hidden in its cc compiler options: 

cc -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/
+usr/include/gdbm -g -Dan_Sugalski -Larry -Wall -Wstrict-prototypes...

[download]

Provoked by merlyn, pjf once submitted a patch to P5P to make Perl play nethack when sort is called in scalar context. Doubt this patch was ever accepted however.

In reply to Re: are there any easter eggs in perl? by eyepopslikeamosquito
in thread are there any easter eggs in perl? by morgon

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.