This is a pieced together version of Agisis's model face hugger.

For me i found splicing the parts to a single part far more easier to manage post print.

Print settings:
.12 layer height
4 layer wall (1.6mm)
40% infill
Rafts used with 5mm margin
Supports used with 75 degree over hang angle

Post print:
Remove supports and rafts
Knife off additional material
Exacto or surgical knife the additional material
Gas torch other imperfections back into the surface(remember plastic is a terrible heat conductor, allow to cool between areas)

Build:
A hard push and a wiggle and the joints should lock in.
The only joint i had loose was the rear body to tail part which i welded into position using print material and gas torch.

Paint:
Plastic primer or filler primer
Then your choice of colours for the final product

22/9/17. Added the More detailed body complete file as reequested. Some of the bottom features are extruded to show of these extra details.