What is the legal penalty for this if any?

Is this a hypothetical situation? If not, I’d keep an eye on that gum. A single stick of gum is an unusual thing to send in the mail, but it’s not terribly unusual to put liquid LSD on chewing gum.

If the boy willingly gives it up, I would imagine that only the sender would be at fault, unless it can be proven that the boy solicited the drugs.

Federal law indicts the sender.

Hide the chewing gum!!! You don’t know what’s in it!
LA Times article