It seems like it's going to be too heavy and sink into the cake, any ideas? I made a wire frame and left about an inch of (covered) wire sticking out of the bottem of the feet to put it on the cake- I'm worried now

Could you cut the wires on the bottom and put it on a small board of some sort with a base, and use dowels to support it?

An inch of wire sticking out is definitely not enough to hold up that tall giraffe. It'll be top heavy and tip over.

You'll need to either attach a dowel to the giraffe and slide it all the way down through the cake to the cake board or attach the giraffe to something like a styro base covered in fondant and than place a dowel into the cake under the base so it doesn't sink into the cake.

I agree. It needs a base that has doweling underneath to support.