Nickelodeon's parent company, Viacom, is suing Hearrt Events for allegedly stealing its lovable animated characters from "Paw Patrol" and using 'em for furry mascots that get booked for meet and greets with kiddos.

In the docs, obtained by TMZ, Viacom says Hearrt hosts events where kids, or more likely their parents, pay $20 to "meet" the "Paw Patrol" squad, and get a photo with 'em. You can even get an autographed "paw print."

Viacom says the events co. isn't just using Ryder and his puppy pals' images without permission -- it's also selling unauthorized "Paw Patrol" merch at their events.

The media company wants a judge to shut down Hearrt's operation, and, of course, to award damages. We've reached out to Hearrt Events, but no word back.