Italian crested newt
When newts are inactive or in oxygen-rich environments, respiration can be done through their skin which accounts for 74% of the cutaneous respiration. However, oxygen-poor environments, such as stagnant ponds, pose a threat to the survival of larval newts. This is because oxygen molecules do not readily dissolve in water, and as "T. carnifex" is an immobile animal, extracting oxygen from water is difficult. Newts consequently have external gills at birth that persist until metamorphosis, which assists survival in low-oxygen conditions.
Ned's Newt
That night, Newton crawls from his bowl and gulps down several mouthfuls of Zippo. Thus, the "too much" warning comes true: Newton grows 6 feet tall, can talk (voiced by Harland Williams), and has the power to shapeshift. After Ned realizes this, he and Newton become the best of friends, but unfortunately, the effects of Zippo do not last forever. In fact, Newton often gets Ned into trouble, at which point the Zippo wears off and Newton shifts back to his smaller form, leaving Ned alone to bear the wrath of his elders.