The Shadow
Motherships are incredibly powerful ships, only rivaled in power by
Vorlon ships. They resemble huge black spiders, with 10 spines sticking out on each side, and they are
organic in nature.
The Backbone of the Shadows, Shadow Motherships are extremely maneuverable for ships of their size, they appear to be at least 1 km wide between the farthest "spine"-tips. The weapon of choice is an extremely powerful beam weapon that easily slices through most ships and space stations. They can also launch jump-point de-stabilizers, destroying ships that attempt to escape. The Motherships also carry many Shadow fighters that can be launched together. The Shadow Motherships enter and exit hyperspace by "phasing" in and out of normal space, a more advanced and faster method than using jump-points. This "phasing" is often mistaken for "cloaking", which it is not.
After the first Shadow War, the Shadows went underground and buried their remaining ships on various planets inside the Galactic Rim. At least two ships were buried in the Sol System, one on Mars and one on Ganymede.
In the episode, "Messages from Earth", it was revealed that these ships require a living core as a Central Processing Unit. This core must be telepathic.
In the episode, "Ship of Tears", it is revealed that the Shadows add cybernetic implants to conform the telepaths to adapt to the Organic Technology of the Shadow Vessels.
Episode Appearances
The Shadow Mothership was first seen (actually it was partially off camera) in "Signs and Portents". It was attacking the Raider Jumpship.
The first full image of the Shadow Mothership was seen attacking the Narn Outpost in "Chrysalis"
They are seen in mass quantities in Londo's Dream
The first use of the Jump point de-stabilizer was in "The Long Twilight Struggle"
All the Shadow vessels left beyond the rim in 2261, in "Into the Fire".