Well finally a chance to post something not related to "boycotting" a VR album. Ridiculous, that's all I have to say.
Anyways, on the topic, the Slither riff reminds me of the main riff to the Deftones' "Shove It (My Own Summer)". It's a similar drop D sorta thing.
I play the main riff like this:
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---------------------------------------
---------------------------------------
0-3-4-0-6-7-0-10-0-6-7-0-5-0-3-4
0-3-4-0-6-7-0-10-0-6-7-0-5-0-3-4
0-3-4-0-6-7-0-10-0-6-7-0-5-0-3-4
The little fill I play just the same as above, but only on the D string (the 4th string), and not with big power chords.
The intro is something like this:
--x--------------------------------------
--x--------------------------------------
--7---7--9s10---12------------------- x 3
--0---0-(let ring)---------------------
--0---0-(let ring)---------------------
--0--------------------------------------
--x-------------------------x-----------
--x-------------------------x------------
--7---7--9s10---7-------x------------- x 1
--0---0--0--0----0-------x------------
--0---0--------------------x------------
--0-------------------------x------------
Hope this helps