Idle pose

An idle pose is a pose that Samus Aran or other characters take when they are not moving in the Metroid Prime or Super Smash Bros. series. Samus does not have any idle poses in most of the 2D Metroid games, or Metroid: Other M, nor does the Federation Force in Metroid Prime: Federation Force.

Metroid Prime
In the Nintendo GameCube versions of Metroid Prime and Metroid Prime 2: Echoes, Samus will calibrate her Arm Cannon if she is left alone for a long period of time. She will do several things:

If Samus is idle and waits long enough, she will flip a panel on her cannon with four lights with colors that correspond to the game's four Beams. This occurs even before she obtains any of the three extra Beams. The same goes for Echoes, although in that game it is a circle divided in half, with one side being gold and the other side being black. She will also put her hand on the Arm Cannon, "calibrate" it, and finally lower it off-screen until gameplay is resumed.

Idle poses are no longer present in the Wii versions of either game, due to the introduction of Wii Remote controls; if left idle, Samus's Arm Cannon returns to the center of the screen with a blinking yellow symbol. Eventually, the Wii Remote will enter Sleep Mode, and automatically pause the game.

Super Smash Bros.
Every character has an idle pose and at least two animations when they have not moved for some time. The character will often perform some sort of action in place, without gameplay impact. In Link's case however, the direction in which he is standing idle affects his ability to block projectiles with his Master Shield. Idle poses were introduced in Super Smash Bros. Melee.

In Samus's only idle pose in Melee, she simply stands in place with her hand on her Arm Cannon, much like her stance in Super Metroid. Starting from Brawl, Samus would either raise her cannon and trace her finger over it, or lower it for a moment. Dark Samus's idle poses are identical to Samus's, although she levitates in midair while doing them.

Zero Suit Samus's pose in Brawl and Super Smash Bros. 4 has her stand in place, slightly "dancing", while holding her Paralyzer steady. In her first idle pose, she raises the Paralyzer beside her head and looks left and right, before assuming her previous stance. In the second pose, she lifts the Paralyzer, opens its top and calibrates it before lowering it again. She has a new idle stance in Ultimate, wherein her Paralyzer is held beside her head at all times. Her idle poses are otherwise identical, if quicker.

Ridley's stance consists of the dragon standing in place, consistently clenching his claws and teeth. In his first idle pose, Ridley shakes out his shoulders. In his second, he turns slightly to his right and utters a quiet growl.