ten·ta·cle

– noun
1. any of various slender, flexible processes or appendages in animals, esp. invertebrates, that serve as organs of touch, prehension, etc.; feeler.
2. a sensitive filament or process.

ten·dril

– noun
1. a threadlike, leafless organ of climbing plants, often growing in spiral form, which attaches itself to or twines round some other body, so as to support the plant.