The Mario the Quick power-up is a Power-up introduced in an unamed Mario game which allows Mario to increase his speed dramatically allowing him to run nearly 5 times faster than when he is under the influence of an Invincibility Star. (Please don't use the images and power-up without first consulting the respective owner, cheers)
the Speed Shroom is the name of the power-up which allows Mario to become Mario the Quick. It appears similar to other Mushroom based power-ups such as the Mega Mushroom, Mini Mushroom & Propellor Mushroom.
When Mario is under the influence he is shown to have a fading effect after him as he runs and also leaves a red trail for a few seconds of his appearance. There are no physical changes to him or his attire. Interestingly Luigi and other characters will glow for an unknown reason, it is not clarified why this happens and why Mario does not glow.
When the power is activated, Mario will spin in a Red Ball (other characters spin in their respective colours) and then he will return to his regular standing pose, it is interesting to note that if one looks very carefully they can see his body shaking by minute amounts.
While under the effects of this Mushroom, Mario is able to run 5 times as quickly as when he is under the influence of the invincibility star. This speed applies to all his movements including crawling and jumping. He is also able to ram into some weaker enemies and stun them so he can jump on them. This power-up cannot be combined with other power-ups however so enemies like Spinies cannot be defeated.
- The Power-up was named from the character, Koopa the Quick. While Mario was able to outspeed Koopa the Quick, there was a later itteration of the Koopa the Quick character who challenged Mario again and this time ran faster than Mario requiring him to use the Speed Mushroom.
Unlike other Power-Ups the Speed Mushroom glows in the dark.