A Barbar is a Kirby's Return to Dream Land enemy. It's very similar to Gaveela of Kirby Canvas Curse because the 2 have the same attack. This enemy is also invincible; you can't beat it. Another similar enemy, Iron Barbars, are bigger than Barbars, though this enemy is always underwater, whilst the latter live in lava.
If Kirby (or another playable character) gets close, it will swallow him. You need to shake the Wii Remote to be free again.