Building the rocket is pretty straightforward, it's really just a Fat Boy with big fins. You can print out the template for the fins here.

If you don't have the G10, balsa would work fine but basswood might be better. You might also use the stock fins from the Fat Boy kit as the dorsal and ventral fins shown. These are just simple shapes and they just need to look right as they don't affect the aerodynamics of the rocket that much.

Replace the centering rings and motor mount with the set up shown below in the parts list. I was concerned about the noseweight so I built it for 24mm just in case. Motor is friction fit and the thrust ring is a couple of wraps of masking tape. 

The BT is preslotted so just epoxy the fins in place and install a fillet of your choice. Tack with CA till the epoxy sets. The forward fins are simply butt glued to the airframe with CA. The airframe, fins and nosecone is painted with Rustoleum black lacquer but I forgot to clean and sand the G10 so it looks pretty horrible due to the residue on the surface which caused the lacquer to cat's eye and separate.

The Tweety head needs a bit of carving with an x-acto to fit properly.  Trim and fit, repeat as necessary. Attach with hot melt glue.  The drinking spout needs to be dealt with but a bit of trimming with the x-acto, a hot knife to melt the plastic took care of it. To fill in the hole you can heat up the spout in a clean flame till it's malleable then smear it into the hole. If you have ever repaired your ski bottoms you know the drill.

The graphics are made from 1 mil vinyl available at sign shops everywhere.  White for the belly and teeth, red for the tongue and a yellow to match Tweety and represent his torso in the sharks mouth. : ) They were mostly cut, fit, peel and install so be creative adn develop your own scheme.  I cut sections of yellow vinyl to represent the mouth, overlaid it with the tongue vinyl in red then overlaid that with the triangular teeth.

The eyes are ellipses and lines done in a simple graphic program, printed on my color printer, cut out and glued in place with a glue stick.