Most of the shape was given by LSculpt using the file from RepRap: reprap.org/wiki/Tux. It's approximately 50cm / 63 studs high.
The original image was painted in 2D by Larry Ewing who grants permission to use his image on the condition that you tell anyone who asks that he painted it using The GIMP. The 3D version was modeled in Blender by Oliver Baker.
That's my Tux collection
Minifigures to get a feeling for the size of it.
Building this way means that almost no bricks were used, mostly plates. The shell is only 2-3 plates thick and requires an internal structure:
Ha! Love seeing you take Tux to the next level here. Fantastic shaping, gives a real adorable quality to him. You might consider forwarding this on to Linux's homepage. Or even Microsoft's. XD Excellent!