Hi, I'm making an owl cake topper out of modelling chocolate for a birthday cake so far (without any decorations) it weighs 10.6 oz and is over 3 inches high. My cake will be a tapered square cake and 7 1/2 inches on top. How do you think I support the owl? The cake will be covered in fondant. Do you think toothpicks will be enough or do I need to use a couple of doughs in the cake and stick through the owl?

*dowels

Hmm. This reminds me of my late aunt's second wedding: at her insistence, a heavy, porcelain "Precious Moments" bride-and-groom were mounted atop the cake. Which then slowly collapsed under the weight.

Or maybe I should make it smaller? It might be out of proportion for the size of the cake do you think? Correction it's only about 2 inches high

You support a heavy topper the same way you support a heavy tier.  dowels or another type of support system.

True story -

Bride had a glass topper custom made (blown glass) at our local glass blowers.  I called the glass artist to ask the weight of the thing.  Answer, "Oh not much at all.  Eight pounds."

Sooo . . . I put an SPS plate and pillar assembly into the top tier, covered that with an extra circle of fondant. and advised them to place ther topper on the cake right before the pictures and take it off immediately.  Seemed to work as I never heard otherwise.

I routinely carried straws with me, so that when I got to the reception venue and discovered a heavy-ish topper, I had instant support.  Place the topper briefly onto the top of the cake to get an outline of where its going, cut straws and insert several of them into the tier and set the topper in place.

I had  a client who wanted a heavy glass cube picture frame as a topper. I simply prepared the top tier as if I were placing another tier on top, with straws and a cardboard round. and frosted the top of it. When the cake was in place at the event, the topper was put on top. As far as I know, there were no problems with sinking

Could I use thin straws to support the topper? I've never been game to use straws and I don't have any thick ones.

The topper has to be sitting on a rigid base for the straws to do any good.  Small circle of bone dry gumpaste,  small piece of plastic plate or foil covered cardboard...which can be camouflaged with icing, but they have to be RIGID.

Thanks for that. Does that apply to using dowels as well? I've stuck two kebab sticks through the owl with the intention of sticking it into the cake to secure it and have now decided to use dowels underneath. Do I still need to use a platform between the owl and the cake?