Titan is
the only other body in the solar system to show evidence of an active weather cycle, where liquid evaporates from lakes to form clouds, and rains back down to the surface, forming rivers and channels.
Outside of Earth, Titan is the
only other planetary
body in the
solar system with actively flowing rivers, though they're fed by liquid methane instead of water.
Titan is the second largest moon
in the
solar system, after Jupiter's moon Ganymede, and it's sometimes called a planet - like moon: It's the
only other world
in our neighborhood to feature stable
bodies of liquid on its surface, and it has a thick atmosphere made mostly of nitrogen.