I never noticed a goose's tongue before. Look at the tooth-like projections which, along with the serrated edges of the bill, help cut grass and plant material when they are grazing.
This guy is not too happy with intruders in his territory. A few Canada geese landed in the marsh that has a nesting pair. The local goose flew over to chase them out. Honking all the way!! He looks like he's doing some crazy dance moves.
He eventually gave up and swam back to his mate, having given the intruders a good "tongue lashing".