Weston
Dr. Weston, once a symbol for Western materialism in the first novel, now completely shifts character, becoming a wily, deceptive manifestation of evil. It comes to light that he is possessed by a demon (likely Satan himself), and he has come to Perelandra to tempt its sinless humans to disobey Maleldil. Weston, as the only source of evil on the planet, comes to represent evil in its darkest, most tricky form; victory over Weston at the end is seen as victory over all evil.
Ransom
At the beginning of the novel, Lewis includes a note categorically denying that any of his characters are allegorical. Despite this, the character of Ransom is at the least highly symbolic, and at the most completely allegorical, of Jesus Christ. His mission is the same - fight against sin and death in an alien world in order to save its inhabitants from certain damnation. Ransom is an appropriate name: Christ "gave his life as a ransom for many" (Matthew 20:28, Mark 10:45).
Ransom's Heel
When Ransom arrives back on Earth, his only noticeable blemish is a bleeding wound on his heel. It comes to light that he sustained this injury while fighting with Weston in the subterranean caverns of Perelandra. In this light of Genesis 3:15, which says that the savior of humanity will crush the head of the serpent (Death) but the serpent will bite his heel, this symbol is a visual representation of Ransom's struggle with death and a clear indication of his status as a Christ-figure in the novel.
The Floating Carpets
Most of the landmasses on Perelandra aren't really fixed at all; they are large floating carpets of vegetation that serve as mobile islands, floating on the surface of Perelandra's vast ocean. The inconstant and temporary nature of these islands symbolizes the temporary nature of material life on Earth. This fallen Earth is not Man's permanent home, and the Perelandran landscape reflects that.
The Column of Light
In the first few chapters of the novel, Lewis (the narrator) visits Ransom's house. While there, he comes across the Oyarsa of Malacandra, whose presence is represented by what can best be described as a vertical column of light. This column, which guides Ransom to Perelandra and makes Lewis aware of Ransom's return, symbolizes and evokes images of the pillars of cloud and fire that the Lord uses to guide the Israelites out of Egypt.
