On the left, this eldritch fungal nightmare is called the Mu Spore. 100 ft (30.5 m) from tentacle tip to tentacle tip...minimum. Usually bigger. They're flying apocalypses, raining down spores to weaken you and sucking people up in giant whirlwinds like Kirby. Really quick with grabbing people too. That said, they're incredibly intelligent and speak 4 languages, so sometimes people are able to make peaceful contact and learn valuable and strange information while collecting fresh spores. Shoot your shot, after all if you're alone you're barely worth digesting anyway to a creature that size.

On the right is the guardian naga, wise and benevolent protectors of natural and supernatural sites! To them, the cosmos is worth protecting, and doing so is a fulfilling experience in itself. They're typically around 14 feet (4.2 m) long, have a venom that drains your energy, and TONS of magic they wield like an oracle or sorcerer. Healing, flying, neutralizing poison, calming emotions, dazing, increasing your skill, etc.. and to answer a common confusion, when talking about snakes anything past thier vent (genital holder) isn't included in length.