It is said that Lord Shiva is the greatest Vaisnava and spiritual master of the universe but In the chapter Lord Shiva saved from Vrkasura
TRANSLATION
[Śukadeva Gosvāmī continued:] Thus advised, the demon proceeded to worship Lord Śiva at Kedāranātha by taking pieces of flesh from his own body and offering them as oblations into the sacred fire, which is Lord Śiva's mouth.
Later when Lord Shiva appears he tells him
SB 10.88.20: Lord Śiva said to him: My friend, please stop, stop! Ask from me whatever you want, and I will bestow that boon upon you. Alas, you have subjected your body to great torment for no reason, since I am pleased with a simple offering of water from those who approach me for shelter.
Replies
Hare Krsna
It was written by me that Lord Shiva doesn't come under maya like us
Srila Prabhupada writes but when Parvati agitated him for sense pleasure, he agreed to the proposal, and as a result Kartikeya was born.
Srila Prabhupada writes - "Lord Siva is not an ordinary person, he cannot be bewildered even by the most beautiful woman. Cupid himself tried to invoke Lord Siva's lusty desires in the presence of Parvati, but Lord Siva was never agitated. Rather, the blazing fire from Lord Siva's eyes turned Cupid to ashes." SB 8.12.15
The correct understanding is - Cupid tried to invoke lusty desires in Lord Siva. Parvati devi wanted to marry lord Siva. But none of these could agitate. Instead Lord Siva god angry on cupid. This is unexpected because effect of cupid is madness due to lust. Once lord Siva came out of his trance then he agreed to marry mother Parvati because demigods wanted Lord Siva's son as their commander to defeat a demon. For this reason and also because Parvati is his associate, Lord Siva agreed for the proposal.
It is something like we feel hungry, we are controlled by hunger, we are forced to eat. Lord Siva isn't controlled by hunger but he still eats for sake of others. Lord Siva doesn't have enjoying mentality like conditioned souls but he still agrees to act within material modes for sake of other living entities.
This is what is meant when Srila Prabhupada says -" he agreed to the proposal"
This is also the main difference between Lord Siva and Lord Visnu. Lord Visnu never comes within the modes of material nature. He is always transcendental to modes of material nature, while Lord Siva even though is transcendental still agrees/chooses to come under modes of material nature but not with enjoying mentality or due to ignorance. He is always rightly situated in his original position.
Conditioned souls are in deep ignorance and have no knowledge about their original position.
Hare Krsna
Hare Krsna. Ashwin Pr is right.
In this link there is detailed explanation about constitutional position of demigods. It would be helpful to see the comment in the link
But Lord Shiva is not an ordinary demigod.
Constitutionally - according to tattva - Lord Shiva is Shambhu tattva (55 qualities)- which is more than jiva tattva(50 qualities) but less than Visnu tattva(60 qualities)
From Eternal Devotional service point of view Lord Shiva is topmost vaishnava.
Origin within material the universe is as guna avatara, in charge of mode of ignorance and activities in mode of ignorance like annihilation of cosmic universe etc
Lord Shiva within the universe also has role of demigod who takes share of sacrifice, gives boons when people worship him. People in mode of goodness, passion, ignorance anyone can worship him.
Preaching wise he is a mahajana like Narada, Prahlad etc and he is originator of vaishnava sampradaya called Rudra Sampradaya. He is also capable of awarding devotional service to his faithful worshippers.
In pastimes he comes as Hanuman.
We can only imagine if Lord Shiva is so many things simultaneously, How infinite Supreme Lord Krsna is !
How does Lord Shiva accept human flesh ?
When he does this, he is playing the role as a demigod to that particular worshipper.
This material world is the only place where illegitimate desires can be fulfilled in illusion. So there are likely to be people who are in ignorance. They may want to get power. So for such people there is a provision of worshiping demigods. Lord shiva can accepting worship from people in mode of ignorance and give them boons.
Lord Shiva is not affected
If we eat flesh we will be breaking regulative principles. Shiva can drink poison of the whole universe, yet not be affected. So accepting offered flesh is nothing for him. The regulative principle of no meat eating is applicable to us.
51st quality of Lord Shiva is - He is always situated in his original condition. Jiva can come under maya but Siva doesn't come under maya like us. Siva can come under yoga maya.
Hare Krsna