It is strictly illegal plain and simple in all states for good reason.
These include that you are not to remove a reptile (or product including a shed skin) from your premises, except in transit for trade or for a vet visit.
This is to help prevent misinformation being spread by people without training or approval from the relevant authority, to assist in preventing profiteering from wildlife and minimize disease tranmission.
In qld education Queensland must in addition approve the demonstrator as well as have copies of working with children approvals, public liability certification etc
Might seem excessive but that is the state of play.
If you are caught doing the wrong thing by bringing a snake to classroom for instance the punishment can be severe including confiscation of the animal(s), fines etc
Cheers
Scott