Titan name: Caput Inter Nubila

In more recent years renamed to the Caput Inter Nubila ("Head in the clouds"), this Titan was originally named Vindex Manus. Retired after centuries of punishing warfare, and then restored through several centuries more, by a dedicated band of Tech Priests, the Nubila is part of an Explorator team. They work diligently to reclaim both long-forsaken Imperial worlds, and the immeasurably valuable bounty of long-lost technology they may hold. The presence of a Titan is often all that's required to remind any inhabitants that they are indeed, loyal Imperial citizens. For those with an unfortunate or persistent lapse in memory, it is usually a very short reminder.
How does a Titan earn a second name? Upon finding themselves brought forward less frequently for frontline battle, and spending their years exploring these forgotten worlds, the Nubila’s Princeps and closely bonded machine spirit began to slowly change over time. An otherwise entirely reliable servant of the Emperor, much to the chagrin of her crew and dedicated techpriests, the Nubila has through these years, developed a curious habit of entering long periods of total meditation when left alone. During these times she refuses to respond to any and all issued commands.

The Nubila continues to perplex and mildly frustrate her crew, but as she is yet to perform any less than ferociously in battle itself, they have deemed ironing out her eccentricities more problematic than allowing them to develop. Bewildering them further however, are the occasional alerts from the sensor arrays during those periods of rest, which indicate her more than casual interest in tracking local wildlife.

The Explorators, determined that there must be a discernible meaning behind these readings, have tasked their novice engineseers with logging her discoveries. Unwittingly creating the Imperium's first and only field guide of Terran species long thought extinct.