This is the best Halloween song and there wasn't a good tab of it so I made one up myself.
Sounds pretty close to me. 

You can do whatever version of the chords you want, but I chose to play them this way.

Chords:
   E7        C7                   G              B7              D7
e|-0-|      |-0-|               |-3-|           |-2-|           |-2-|
B|-0-|      |-1-|               |-3-|           |-4-|           |-1-|
G|-1-|      |-3-|               |-0-|           |-2-|           |-2-|
D|-0-|      |-2-|               |-0-|           |-4-|           |-0-|
A|-2-|      |-3-|               |-2-|           |-2-|           |-x-|
E|-0-|      |-x-|               |-3-|           |-x-|           |-x-|
        
Intro E7

    E7
I'm carving pumpkins, it's almost Halloween.
   C7                           G
All my friends are wondering, what they're gonna be. 
    E7
The monster mash is playing, you're moving to the beat.
    C7                            G                      B7
And now we're gonna teach you, to do the trick-or-treeeeeeeeat.


            E7                C7
Everybody scream, everybody scream,
              D7
It's almost Halloween.
                    E7                       C7
Do the trick-or-treeeeeeat, do the trick-or-treat,
               D7                 E7           C7         D7
It's almost Halloween. Everybody scream.


         E7
There's a devil in the corner, in candy apple red.
     C7                     G
Dressed up like a fire, burning through my head.
  E7                                        
I got a little closer, and offered her a drink.
      C7                               G                  B7
Who took me to the graveyard, and we did the trick-or-treeeeeeat.


           E7                C7
Everybody scream, everybody scream,
             D7
It's only Halloween.
                    E7                       C7
Do the trick-or-treeeeeeat, do the trick-or-treat,
              D7                 E7           C7         D7
It's only Halloween. Everybody scream.


Bridge- (strum once, or whatever you want)
   E7                                C7
Before I learned her name, we were already asleep.
        G                              B7
When I woke up in my coffin, she was nowhere to be seen.
              E7               C7
Was it all a dream, who can I believe?
                     D7                    C7     
It can't be what it seems, it was only Halloween.
                   E7           C7       D7
What does it all mean?


            E7                C7
Everybody scream, everybody scream,
          D7
It was Halloween.
                    E7                       C7
Do the trick-or-treeeeeeat, do the trick-or-treat,
               D7                
It was only Halloween. 
           E7                C7
Everybody scream, everybody scream,
          D7
It was Halloween.
                    E7                       C7
Do the trick-or-treeeeeeat, do the trick-or-treat,
                D7                 E7           C7         D7
It was only Halloween. Everybody scream.


and end with E7 again