Viking helmets, made during a Vikings and Pirates unit. The shape was created on the top of a balloon with paper mache (6-7 layers, the more the stronger). Eye rims and nose rims are cut out, then the whole dome was painted. Once dry details are spray painted on around the rim and crossed over the top. Bolts were drawn on with a marker. Horns are rolled from news paper and taped with masking tape and fixed by cutting holes in the sides and securing with tape. took 4 weeks.
Like this idea but since I teach grade I would do it with Spanish Exploration. I would add dates, pictures of the explorers with a QR code that took students to a short video bio. Maybe some maps and images of ships, the three "G", and supplies.
Both the book series version of Hiccup Horrendous Haddock III, and the franchise version of Hiccup Horrendous Haddock III wore a Viking helmet. In How to Be a Pirate, Hiccup's Viking helmet had part of one horn sliced off while swordfighting. Hiccup usually wears a helmet in the books. Toothless sometimes sits on top of it or hides under it.