[frizzen]

Looks like it's just on parts with overhangs. The plastic is not allowed time to cool properly before gravity makes it sag.

Couple ways to go:
Slow your extruder, and thus print speeds, also weaker layer bonds. - Meh
Rotate parts for no overhangs before slicing, printing. - Not always an option
Add a fan at the hot end to help set plastic faster so it can't sag. - May void warranty, have to run aftermarket software.
Edit parts to ramp overhang supports that are ground off during clean up. - learn cad
Dual print heads with filiment and a disolvable support matrix. - $$$