Does Wall of Fire cast in the middle of a huge creature cause it to take damage twice?

Question

Wall of Fire reads (emphasis mine):

An immobile, blazing curtain of shimmering violet fire springs into existence. One side of the wall, selected by you, sends forth waves of heat, dealing 2d4 points of fire damage to creatures within 10 feet and 1d4 points of fire damage to those past 10 feet but within 20 feet. The wall deals this damage when it appears and on your turn each round to all creatures in the area. In addition, the wall deals 2d6 points of fire damage +1 point of fire damage per caster level (maximum +20) to any creature passing through it. The wall deals double damage to undead creatures.

If you evoke the wall so that it appears where creatures are, each creature takes damage as if passing through the wall. If any 5-foot length of wall takes 20 points of cold damage or more in 1 round, that length goes out. (Do not divide cold damage by 4, as normal for objects.)

If you cast a Wall of Fire down the middle of a huge creature, per the second paragraph it would take damage as if passing through. However during its turn it cannot 5' step "escape" because of its size (cannot 5' move to the heat side or 5' move to the non-heat side), so does it take the passing through damage a second time if moving out?

I feel like the general D&D intent is generally for spell effects to happen once a round but I cannot find any ruling that states that explicitly or contradicts the taking of the damage twice in this scenario.

Answer 1

The spell seems to be written with the idea that the huge creature would take "waves of heat" damage on the caster's turn if the creature were in range of the "waves", and "passing through" damage on the creature's turn if they moved through the wall of fire. By a simple reading, the creature would take the "waves of heat" on your turn, and "passing through damage" on the creature's turn. The same would repeat the following round if the creature was still occupying space in both the "waves" range on the caster's turn and "passing through" range on the creature's turn.

This post is similar, though dealing with a different issue.

After re-reading the spell description, it does appear the creature takes "passing through" damage on your turn (because it's "if you evoke"). With that in mind, I think the first round, the creature would take "passing through" damage on the caster's turn, and then on their turn, if they don't (or can't) get out, "passing through" again. On subsequent rounds, I would treat is as above.