You could do any weapon you’re proficient with; I’m just making sure you’re specifically wanting a club instead of a mace or morningstar or warhammer or flail, etc.

And would you prefer the shield to be a reaction that becomes better than a normal shield long term, or the normal shield bonus? The Behemoth is a wily thing for me to get into 5e terms due to its beastlike nature and I want you to enjoy the experience.