Magikoopas are enemies in the Mario series who first appeared in Super Mario World for the SNES. They're essentially more powerful Koopa Troopas who have the ability to generate magic via wand. With this magic, they can transform regular blocks into enemies and create items out of thin-air as shown in many of the games. An example of this would be in Super Mario Galaxy where they would create Koopa Troopa shells through their wands and thrust them towards Mario or Luigi. However, their items were used against them when either of the brothers tossed the projectile back to the sender. In most instances, a Magikoopa's spell will appear as a projectile consisting of a sparkling cloud with randomized, spinning shapes such as squares, triangles and circles in multiple colors running through it. The 'cloud' can sometimes be tinted a different shade depending on the spell being cast, such as the case in Super Mario Galaxy where a fireball attack would appear red while a shell attack would appear green.
Their appearance clearly shows that they are indeed wizard like with the correct apparel you'd assume one to wear. They are usually wearing blue cloaks with white trim and a pointed hat to match, and they carry a golden, scepter-like wand with a red gemstone embedded into the top end. They also have large round glasses that have black frames and are unable to see through from the outside. Some Magikoopas can be found ridng broomsticks, as is the case with Kamek and Kammy, two Magikoopas that play special plot roles in certain games. Unlike regular varieties of the Koopa Troopa, most variety of Magikoopa can be defeated with a single jump - or in some RPG cases, a few attacks - and don't retract into their shells. Some variety of Magikoopa have the ability to teleport short distances. These troublesome foes are also in Super Mario Galaxy 2.
In Super Princess Peach, Magikoopas are called Kameks and only appear in the battle with Giant Kamek and he summons them to attack Princess Peach and some have Vibe Crystals and some don't.