Taito made both Chack 'n Pop and Bubble Bobble, though Chack'n Pop is a few years older of the two. Bubble Bobble clearly reuses several enemies from Chack 'n Pop and is of the same type of game (platformer) though the gameplay is different. I wouldn't call it part of the series, but probably made by some of the same people or at least an influence of the later game.