We don't have synonyms for tree snail yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are treenail and tree snake.
(N) :
a common name that is applied to various kinds of tropical air-breathing land snails, pulmonate gastropod mollusks that have shells, and that live in trees, in other words, are exclusively arboreal in habitat.
(N) :
a common name that is applied to various kinds of tropical air-breathing land snails, pulmonate gastropod mollusks that have shells, and that live in trees, in other words, are exclusively arboreal in habitat.