QOTSA - You can't quit me, baby
Bass tab by ZaCh45

Not sure of the actual tuning but I like to play in drop D.

1st riff:
G|---------------------------|
D|--------4---2h4p2-----2h4--|
A|---------------------------|
D|--4--4------------4-4------|

To change it up just add/remove a note here and there, ignore the hammer on/pull offs, 
volume, etc.

Variations(a few examples):
G|---------------------------|
D|--------4---2h4p2----------|
A|----------------------2h4--|
D|--4--4------------4-4------|

G|---------------------------|
D|--------4---2h4p2------2h4-|
A|---------------------------|
D|--4--4------------4-4------|

G|---------------------------|
D|--------4---2h4p2-----4----|
A|---------------------------|
D|--4--4------------4--------|

2nd riff:
G|------------------------------------------------------------------|
D|------------------------------------------------------------------|
A|------------------------------------------------------------------|
D|--4-4-4-4-4-4-4-4-6-6-6-6-6-6-6-6-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-7-|
 |       4*8       |      6*8      |             7*16               |

3rd riff:
G|----------------------------------|
D|----------------------------------|
A|----------------------------------|
D|--7-7-7-7-7-7-7-7-4-4-4-4-4-4-4-4-|
 |       7*8       |      4*8       |

That's about it.  Change up the 1st riff to keep it interesting. Play along to find out 
to play each riff(it's pretty easy to hear).