This is a plain cardstock postcard produced by persons unknown. It’s undated, but as it’s a protest postcard it can be dated to 1998 as that’s when the Mr. Toad’s Wild Ride attraction closed in the Magic Kingdom in Walt Disney World.
It’s generally thought that the protest to keep the park from closing Mr. Toad was the first popular protest about a Disney attraction, even inspiring protests in the park. Disney did close it, however the attraction still exists in Disneyland.
The attraction was an opening-day attraction for both Disneyland and the Magic Kingdom. It’s one of Walt Disney’s classic “dark rides” designed for people of every age.
The website listed on the card is still live. It forwards to a page that appears little changed from late 1998.