I’ve written a few times about a “swag bag” from the 501st Bash in Orlando 2017. It’s not a figure of speech. It is an actual bag.
The bag is made from hemp. It has nylon drawstrings attached. The drawstrings closes the bag, and also serves as straps so you can carry it on your back.
The bag was filled with various swag – hence “swag bag”. I’ve only posted the collectors items. It also came with promotional items from the sponsors, various coupons and a generic Star Wars cardboard mask, if memory serves.