My mesh for a Vorlon outside its encounter suit, based on enraged ambassador Ulkesh shown in Babylon 5 season 4 episode "Falling Toward Apotheosis". Ulkesh was forced out of its encounter suit. When it was about to attack Delenn, another Vorlon emerged out of Sheridan.

They appear on screen as squid-like form with tentacles, which they can use for attack purposes.

About Vorlon's physical form according to Mongoose book "Darkness and Light":

The core of the Vorlon is the physical part of the Vorlon; essentially, it is the Vorlon’s body, although the term is of little relevance. When seen, it resembles a being of glowing light, with tentacles and surrounded by a fiery corona of energy. Before the Vorlons transcended base matter and became beings of energy, this core was an organic body (the product of millions of years of evolution and genetic engineering, but a recognisable body nonetheless).

The core is a crystalline structure, which contains the intrusion of the Vorlon’s soul into realspace. The core is composed of four distinct sections. Firstly, there are external manipulating tentacles, which are each composed of a siliconcarbide gel, laced with a nanometre-scale grid of sensors and energy effectors. Each of these tentacles is strong enough to tear through the hull armour of a Sharlin-class warship, but is also precise and gentle enough to manipulate brain tissue without causing injury. For the majority of Vorlons, these tentacles – and the entire core body – are largely redundant, as few Vorlons have needed to manipulate matter directly for millions of years.

The outer shell of the core superficially resembles the pretranscendence form of the Vorlons, but is primarily a crystalline memory aleph wrapped in an armoured casing. The Vorlons no longer possess internal organs; they do not need to breathe or ingest any food or liquid. The shell’s crystalline structure stores energy as well as information – the Vorlon
shell is essentially battery powered, although a Vorlon could function without a recharge for thousands of years.

The third and most important section of the core is the brain, although this complex crystalline computer does not resemble an organic brain in the slightest. The Vorlon soul is incarnated within this brain to allow the Vorlon to think and reason; without a core brain, the soul is static and unchanging, being nothing more than a self-replicating pattern of information and energy.