"A mighty Titan towers above you. Craning your neck back and straining your eyes you can see tiny white specks on its underbelly - they're barnacles, each one as big as your hand. The shock wave of every stupid, lumbering step threatens to throw you off-balance. Enormous deep red limpets cling to its feet, each one equipped with poisonous stingers. They don't bother you - not having feet, they can't leap from the Titan and chase you. They stick themselves to the Titan so that once it begins its journey to the Outpost to which it is (unfathomably) attracted, they can eat any foolish warriors who try to stop the Titan without the aid of close allies. If this Titan reaches the Outpost it's heading for, then all hope for that Outpost is lost - the walls will come down at the Titan's first blow."
Titans are big. Really big. You just won't believe how vastly hugely mind-bogglingly big they are. I mean, you may think-- wait. I've just received a cease & desist order from Douglas Adams' estate. Oh well...
Jakell and Maniak have written the maybe-definitive guide to Titan-hunting. 1) The Guide also includes an explanation of what Titans do. Clicky the linky for all the useful info.
Titans are giant reptilian humanoids that originate from the sea. They are bald, green, and have limpets hanging from their feet and barnacles on their bellies.
Titans move one klick per 12 in-game hours. Or the square root of 2 klicks.
Titans are bad at math. This can be explained away, as they are the only thing in-game that doesn't use the metric system.
Titan's blood is flammable, explosive, and makes great rocket fuel. It also tastes like blue-raspberry flavo(u)ring, despite being a greenish-yellow colo(u)r, not blue.
Because their blood is so 'splody, Titans blow up in a series of giant explosions when killed. Delicious smelling explosions.2)