This map shows the areas where Roundheads are present.
Roundheads are divided into two types: neutral and inverted. The former first appears in Seaside 1 while the latter was introduced in Snowfield 9. It is unusually small, and has become very common in the post-Castle stages. There are 46 enemies with the Roundhead head in Stick Ranger (35 normal and 11 inverted), making it the most commonly used head in the game. The combined population of enemies with this head in Stick Ranger is 1791, more than any other head type.
The Inverted Roundhead bears a remarkable similarity with yet another creation of the Fan-Ball wiki, which was referred to as the Circle head. Though, the Circle head was an entirely new sprite, while the Inverted Roundhead is, as the name suggests, simply an inverted colored Roundhead (with an outline).
In Stick Ranger 2, three new variants of the Roundhead was introduced. The first variant is basically the neutral Roundhead from Stick Ranger with a shifted position for the "eyes", while the second variant is a smaller variant. The thrid variant is even smaller, with an oval shaped head that looks like a squished version of the second variant. It appears on 22 different monsters, and the combined total population of all types of Roundhead monsters throughout the game thus far is 698.