The brazen bull in the Quran?

[Gawdzilla Sama]

If you mean the golden calf of the Israelites, it was solid.

If you mean the brazen bull, as described, I don't think it would work.  The fire was built under the bull to roast the victim inside.  This means the fire would have been built on top the base which would also roast the poor sod blowing through the tube.

Boru

Depends on how big the base was. If you wanted the calf to be life-sized and tower over the mob then a pyramidal base maybe ten feet high would be good. If you built this with a wall close behind it you could have a hatch in the wall to access the base and leave it open for ventilation. (Put vents in the top of the base, disguised if it's not high enough.)