No time to dance!  No time for steps!
       Bring on the Dholes and Nyarlathoteps[1]!

    Something colossal
    Glimpsed as a fossil,
    Rises once again to spread its blight!
    Mankind ends tomorrow, summoning tonight!

     Something that's frothy
     Something shoggothy[2]
     Something for everyone, a summoning tonight!

     Something cthulhoid
     Something puruloid[3]
     Something for everyone, a summoning tonight!

      More elder gods, more awful fates!
      Their power grows as mankind's abates!

    Nothing concealing
    Nothing appealing
    Nothing here of comfort or delight!
    Tragedy tomorrow, summoning tonight!

     Something that's squamous
     Something oogamaous[4][5]
     Something for everyone, a summoning tonight!

     Something that dangles
     In too many angles
     Something for everyone, a summoning tonight!

     [COMPANY]
     Something unhinging
     Something brain-singeing
     Something for everybody, summoning tonight!
     Something ungodly
     Done to a body
     [HERBERT WEST] [6]
     Something for every body![7]
     [COMPANY]
                                   Summoning tonight!

     [CHARLES DEXTER WARD]
     Nothing from books, [8]
     [ERICH ZANN]
     Nothing that squeaks, [9]
     [CHARLES DEXTER WARD]
        (He's been rehearsing this number for weeks.)

     [CULTISTS]
     Something misshapen,
     [VICTIMS]
     With mouths a-gapin'
     [ALL]
     Humankind shall perish out of fright!

     [OBOBED MARSH]
     Unnatural matings! [10]
     [THE OUTSIDER]
     Fear unabating! [11]
     [WILBUR WHATELEY]
     De Mysteriis Vermiis! [12]
     [THE FUNGI FROM YUGGOTH]
     Brains in a thermos! [13]

     [RICHARD UPTON PICKMAN]
     Insanity! [14]
     [CHARLES DEXTER WARD]
     Calamity!
     [DR. ARTIMAGE]
     Tentacles! [15]
     [HERBERT WEST]
     Ventricles!
     [PICKMAN]
     Squamosity!
     [MARSH]
     Rugosity!

     [ALL]
     No hope remains, madness begins
     You'll never get out with your skins.
     Goodness and badness,
      Panic in madness-- [16]
     Nothing here will ever turn out right!
     Tragedy tomorrow, summoning (summoning, summoning) tonight!

[1] Two horrible things that go great together!
[2] Weirdly, google hits for "shoggothy" break down into people who use it as an adjective, and people who use it as the Polish plural of "shoggoth".
[3] Puruloid: pus-like.
[4] Yes, this is not a very good rhyme.
[5] Also, oogamousness isn't very scary.  But it sounds nasty, doesn't it?
[6] The great reanimator!
[7] Not as good as the pun in the original.
[8] See The Case of Charles Dexter Ward for a discussion of why you shouldn't follow recipes from the Necronomicon.
[9] See "The Music of Erich Zann"
[10] See The Shadow over Innsmouth.
[11] This one is far too obscure.
[12] Robert Bloch's nasty book is actually called De Vermiis Mysteriis, and VermiisI doesn't rhyme with Thermos even a little bit, but please bear with me.  It's hard to do a Fungi from Yuggoth joke other than the old obvious fun-guy one.
[13] See "The Whisperer in Darkness", I think.
[14] See "Pickman's Model".
[15] See Shuggoth on the Roof.
[16] It's very weird how little the original lines needed to change for this stanza to work.