From the Super Mario Wiki
Bramballs are enemies that are introduced in New Super Mario Bros. Wii. They return in New Super Mario Bros. U.
Super Mario series
New Super Mario Bros. Wii
in New Super Mario Bros. Wii
Bramballs appear as orange spherical Pokey-esque enemies, with brambles for arms jutting out of their sides and yellow suction cup-like feet. Their sole attack is moving around a set path by flipping themselves around in a Slinky-style motion and planting their feet on flat surfaces. When they reach the end of a small piece of land or wall, they will flip the other way and continue moving. Touching a Bramball's feet or arms will hurt the player.
Bramballs can be defeated by jumping on the ball in the center, freezing them as Ice Mario or Penguin Mario and Ground Pounding on them while frozen, hitting them with Fire Mario's fireballs, or a Star. Hitting them from underneath will release Coins and cause them to temporarily stop flipping over. Hitting them while launching out of a Warp Pipe cannon instantly defeats one and causes them to release twenty Coins. There are two types of Bramballs: ones that don't move their mouths and ones that do move their mouths. The ones that move their mouths are faster.
New Super Mario Bros. U
Bramballs return in New Super Mario Bros. U, being the enemies of the titular Bramball Woods. In this appearance, their heads turn out completely orange and a leaf sprouts from it as the music beats, similar to regular Pokeys in newer appearances. If Mario hits Bramball's underside in this state, it will drop a large amount of coins instead of just one.
New Super Luigi U
Bramballs return in New Super Luigi U, acting the exact same way as in previous titles.
Names in other languages
||From "espina" (spine) and "arco" (arc)
||From french name "Alphonse" and "ronce" (bramble)
||from Häcke (Hedge)
||Portmanteau of "pungi" (Sting) and "palla" (ball)
||Possibly from "bola" (ball) and the interjection "caramba", equivalent to "geez" in English. The word "carambola" also means starfruit.