Kids love dinosaurs, and every child has his or her favorite one. If your child loves the triceratops, then a gift to consider could be a triceratops costume. Kids can play at being a fierce dino, or they can wear it as a Halloween costume. Make sure their vision is not blocked by the mask or headpiece, and make sure they can walk easily without a chance of them tripping over their costume.
Three examples I think my son would love:
Triceratops costumes for kids:
Left: Child Triceratops
Middle: Toddler Green Triceratops Halloween Costume (Size: 2T-4T)
Right: Forum Novelties Plush Cuddlee Triceratops Costume