Shabom

First appearing in Ocarina of Time and found Inside Jabu-Jabu's Belly, the Shabom is a bubble that will bounce off walls and floors in random directions. It will pop upon death, or upon contact with Link, killing itself but also dishing out light damage to anyone nearby.

Deku Nuts are the most effective way of killing Shaboms, as the resulting flash can kill several at once without the need to aim. The Boomerang found partway through Jabu Jabu's Belly is also very effective. While a sword slash is perhaps the most obvious way of slaying them, the resulting pop will damage Link if he's too close. Throwing Princess Ruto through them can also defeat Shaboms, but this is clearly the least effective means of attack. Since these bubbles move slowly, and never show signs of targeting Link specifically, it's often easy to just run past them without having to worry about engagement.

Shaboms also appear in Majora's Mask, although they cannot hurt Link. Instead, the Shabom are found encasing some Stray Fairies.

Trivia

 * Shabom's Japanese name is a portmanteau of, and "bomb" (ボム), indicating its explosive nature.