Salamander

Salamander is a red, black and blue creature type used for several different types of tailed short-nosed small animals with a soft scaleless skin.

Mythical Salamanders
Mythical Salamanders are thought to be able to live in fire. This connection likely originates from the tendency of regular salamanders to dwell inside rotting logs. When placed into a fire, the salamander would attempt to escape from the log, lending to the belief that salamanders were created from flames.

The first red creature to reference this type of Salamander was Pyric Salamander in Mirage. While that one lives on Dominaria, others like Flowstone Salamander, Scalding Salamander and Cinder Crawler live on Rath. Each of these variants has some "fire-breathing" or direct damage ability.

Regular Salamanders
Regular salamanders or newts are amphibians like frogs. They are aquatic as a larva and semiterrestrial as an adult. They don't have scales like reptiles. The blue Gudul Lurker and the black Festering Newt come closest to this type of salamander.

While no natural salamanders have been observed on Ravnica, the Simic have used salamander genetic material for both experiments and in augmentation.

Amphin
The amphin are a race of lanky, shrewd, partially aquatic humanoids on Shandalar who can dwell either in the briny depths or in the overgrown shallows. Little is known about their civilization as yet; time will tell whether we see more of this salamander-folk in the future. Much like Saprazzan Merfolk they are able to live on land. This type debuted with Amphin Cutthroat in Magic 2012, and later with Amphin Pathmage in Magic 2015. The Amphin were revisited in Commander Legends with Amphin Mutineer</c> and Gor Muldrak, Amphinologist</c>.

The amphin have long built their society in secret. While surface dwellers squabbled over trivial borders, they patiently expanded, building their ammonite temple-caves. Now amphin priests eye the shore, and amphin hunters gird for war. — Gor Muldrak, Cryptohistories

Legend has it that the Amphins have used their mind control powers to erase all knowledge of their existence from the minds of humanity. In reality, the Amphins were an attempt to come up with a race of creatures that could occupy the ”medium-sized nonflying blue creature” slot. The experiment did not work out. In the meantime, the spot is held by various Elementals, Humans, Fish, or Spirits, though no civilization or race has held the spot permanently.

Trivia

 * At some point during the set's early design stage, flamekin of Lorwyn were referred to as "salamands" after the belief among medieval alchemists that salamanders were beings of elemental fire.
 * The blue Wormfang Newt</c> from Judgement is also a Beast and a Nightmare,
 * A "newt" is also an organism grown from harvest flesh stored within the Phyrexian flesh vats.
 * Newts are a common ingredient in witches' brews. This is exemplified by the combo of Festering Newt</c>, Bubbling Cauldron</c> and Bogbrew Witch</c> from Magic 2014.
 * In appearance, the Amphin are similar to the Surrakar.