Hi Kathleen!
As someone who visited Le Chefs de France just last month for the first time, I can certainly tell you about the Remy appearance (although I may be letting the "rat" out of the bag..OK, sorry, bad joke...)
A man who looks incredibly similar to the character Linguini will start walking around the tables with a cart. On the cart is one of those plate covers, and under the plate cover is...none other than...Remy!
Linguini will talk to the guests some, and then lift the lid to show Remy. Remy is not real, makes some squeaks, and "Linguini" has some apparatus which causes Remy to move/gesture, etc. They walked around twice and it was a neat touch on the experience.
I ate there that day with some of my panel members and, not seeing it for the first time, of course thought there was a real rat under the plate cover. I should have known Disney was smarter than that, I envision people heading for the exits if the rat was real-smile.
Best Regards!