We just took a brightly colored index card and laminated it, punched a hole in it and strung it on yarn. Ian wore it everywhere and was instructed that if the adults got lost he was to find someone wearing a name tag, any character or person in costume and show it to them. This is what it said
Hi, my name is Ian XXX. I am here with:
Mommy (Lisa XXX) her cell phone number is *****
NawNaw(Aunt Tammy XXX) her cell phone number is ****
Jenniepoo(Aunt Jennie XXXX) her cell phone number is ****
If they get lost please call them for me so that I can find them again.
We told him it was required that all children wear name tags just in case. Of course, with 3 adults with him we knew the chances were pretty slim he'd need it but you just never know.