Charvaargh

Charvaarghs are a subspecies of Magmaarghs that attack by jumping out of lava at any of the characters.

Super Mario 3D World
Charvaarghs make their first appearance in Super Mario 3D World. They appear in only one level, World Castle-7, Simmering Lava Lake where players must make it past them. If a character touches them, a life is lost, regardless of the character's form. Charvaarghs are one of the few enemies that are truly invincible as no method of attack will affect them, not even the Golden Statue form. They are also the only enemies (including bosses) other than the Fuzzy Horde in Fuzzy Time Mine that can defeat in one hit.

However, most Charvaarghs only show up when the player enters a Clear Pipe for aesthetic purpose only.

Captain Toad: Treasure Tracker
Charvaarghs return in Captain Toad: Treasure Tracker, no longer used solely for aesthetic effects. They appear in lava stages either coming out of grates which Toad must walk across, or blocking his path where he must run across Boost Pads. They debut in the first level of Episode 3. In this game, they do not instantly defeat the character.

Mario Party 10
Charvaarghs made their Mario Party debut in Mario Party 10. They appear in Chaos Castle in the unlucky spaces to take away the players Mini Stars.

Trivia

 * The Charvaarghs closely resembles the Blarggs from Super Mario World.
 * They also bear some resemblance to Fire Gobblegut.