TOLOCO Inflatable Alien Costume for Kids, Blow Up Alien Holding Person Costume for Halloween

My child is 5 feet tall, should I buy the child or adult size?

Would this fit a 12 year old boy who’s about 4,9 to 4,10

Is this alien abduction costume suitable for teenagers?

Does it fit tight around the child’s neck? My son is autistic and can’t handle things around his neck, like at the barbershop.