At the beginning of NOS-4-A2, Warp Darkmatter calls XR a tin toy. This is a reference to the Pixar short "Tin Toy", featuring a little musical toy that tries to keep a destructive baby from getting to him.
When Warp calls him a tin toy, XR remarks that he is actually made of a "terrilium carbonic alloy". This is a reference to the first Toy Story film, when Buzz Lightyear says that his wings are made of a terrilium carbonic alloy after Woody says that they're made of plastic.