"It's not a rubber snake. It's a soft toy. People were kind of laughing around him. Nobody thought for an instant it was real. Nobody could think it was a lifelike representation," she said.
However, when the family reached the front of the queue, a security guard told them the toy would not be allowed on the flight – and they were given the option of throwing it away, or checking it into their luggage.
"We had been waiting in the queue for a long time. We had very little time to make it to the gate," she said.
Fritz decided to attempted to put the snake into their checked-in luggage, but found that check in for their flight to Cape Town had already closed.
She wrote on Twitter that while she had intially told security they could arrest her, "ultimately I decided that I was not prepared to sacrifice my liberty in defense of soft toys everywhere".
So she threw the beloved toy away – leaving her son wondering what had happened.
"He keeps asking where it is and when we're going to pick it up. We said that it's with the pilot and has gone on a trip."
The Times had approached Airports Company South Africa (Acsa) for comment, but had not yet received a response.