It does not clearly show in the picture, but I can bet on the back side the layers do not look good at all.
The reason for this is the overhang and the effect is called curling. When the body starts, the angle of the slope the body size increases is very low, so that the outside perimeter is almost in the air. It curls up easily and the layer is affected. Unfortunately the following layers are affected as well and the defect propagates and eventually disappears when the angle of the surface increases.
The only solution I know is of composed of:
- (very) low speed (10 mm/s for 1 Marvin, 20 for 2, 30 for 3)
- very much fan
- print 2-3 Marvins at once
- thinner layers 0.1-0.15 mm
- decrease the extruder temperature (the lower the speed, the lower the temperature)