Bobbles are probably the most fragile heroes. One single attack could pop them, leaving them for dead. However, there are many Bobbles, so there are always more coming. Bobbles attack in swarms, due to the high chance that many would die otherwise. A Bobble is a bubble with a single "eye" in the center. They are always some shade of blue.
When many Bobbles come together as a united creature, it is referred to as a Bobbleton. A Bobbleton is usually the size of a small house. Creating a Bobbleton makes Bobbles stronger, but a Bobbleton's main offense is to shoot Bobbles at the target. This usually doesn't work, as Bobbles, even when shot as fast as a Bobbleton can, aren't that damaging. However, small objects may be contained within the Bobbles, and even if not the Bobbles usually knock creatures down.