Awhile ago I read that Square were still working on Shiva's beast tribe, and I started looking up information on Shiva's roots and if any animals are associated with Shiva. To rip from wikipedia:
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Tiger skin: (The epithet "Krittivasana").He is often shown seated upon a tiger skin,[111] an honour reserved for the most accomplished of Hindu ascetics, the Brahmarishis.[126] Tiger represents lust. His sitting on the tiger’s skin indicates that He has conquered lust.

Serpents: (The epithet "Nagendra Haara"). Shiva is often shown garlanded with a snake.[127] His wearing of serpents on the neck denotes wisdom and eternity.

Deer: His holding deer on one hand indicates that He has removed the Chanchalata of the mind (i.e., attained maturity and firmness in thought process). Deer jump from one place to another swiftly, similar to the mind moving from one thought to another.
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