Nope, it's not April Fools yet.
The Hollywood actor was asked by a CBB viewer on the flight to show off his trademark goose impression.
But Gary, who also spent the plane journey posing for pictures with fans, was so loud that he woke up one of the flight crew who were on a nap break.
And we reckon not all of the other passengers were too keen on the noise either.
According to the Daily Star newspaper, Gary was warned by the flight attendant that he would face arrest if he didn't quieten down.
"They had to make him quieten doe when the captain was taking his break, " a supposed source told the newspaper. "Gary was told: 'Shh, the captain is asleep in there'.
"But he couldn’t hear and said, 'What? There’s ice cream in there?!'
"Nobody – passengers or crew – could keep a straight face. But fortunately he did quieten down in the end."
Gary's representatives have yet to comment on the incident.