| Tender Tendrils |
I would definitely say shark, crocodiles are generally a jaw attack, not a fang attack, and the grapple element is very fitting for the way a crocodile latches onto its prey and doesn't let go.
I think the thrash feat is a good thematic fit here, as is the animal skin feat. If you went further down the animal instinct feat chain, I would talk to your GM about being allowed to turn into a crocodile instead of a shark with the feats that let you turn into your animal.