I am trying to figure out if the undead are supposed to grow in size as per advancement rules. Also someone else mentioned that I am supposed to pick the base creature and that would determine size, I dont think the latter is how it works though any help would be appreciated. thanx
Raise the Dead (Su): As a standard action, you can summon a single skeleton or zombie to serve you. The undead creature has a number of Hit Dice equal to your oracle level. It remains for a number of rounds equal to your Charisma modifier. At 7th level, you can summon a bloody skeleton or fast zombie. At 15th level, you can summon an advanced skeleton or zombie. You can use this ability once per day plus one additional time per day at 10th level.
I am trying to figure out if the undead are supposed to grow in size as per advancement rules.
Changing size is an optional part of a DM creating an advanced creature.
Plan the Monster: "This is also the point at which you should decide whether the creature is going to increase in size. As a general rule, creatures whose Hit Dice increase by 50% or more should also increase in size, but GMs should feel free to ignore this rule if warranted by the individual creature or situation."
Since skeleton/zombie is an acquired template applied to an existing creature, making it get larger due to more HD doesn't make a lot of sense. I think the assumption is the Oracle is summoning a human skeleton/zombie.