Roller is one of the many types of Badniks created by Dr. Eggman and appears as an enemy in Sonic the Hedgehog on the Sega Mega Drive. Based on an armadillo, the Roller has a tougher body than most Badniks of its generation. It attacks Sonic by curling into a ball and rolling down slopes, attacking Sonic from behind.
The Roller is modelled after an armadillo; it has a red, elongated head with two "ears" at the top and its blue body is a sphere that splits open horizontally at the middle. It has two small arms underneath the top half of its body, though these limbs are practically useless. It stands on two legs and has a curved tail.
As the name suggests, the Roller attacks by closing its body and forming a ball before rolling at high speed after its target. While rolling, the Roller can easily be mistaken for Sonic the Hedgehog who often rolls around in a ball at high speed.
Sonic the Hedgehog (1991)
Roller only appears in the 16-bit version of the game. Appearing in Spring Yard Zone, it attacks Sonic from behind while the player is running down slopes or through tunnels. After rolling for a moment, the Roller will jump and launch far ahead of Sonic. After landing, it will stop and open up to observe its surroundings, giving Sonic the perfect opportunity to attack and destroy it. Rollers can actually be destroyed whilst rolling, though this is extremely difficult to do.
The original Roller model never appears again after its debut, but is replaced by the Roller Mk. II in Sonic Mania. This version of the Roller looks the same in shape, but is coloured red with a yellow head. Appearing in the Mirage Saloon Zone, the Roller Mk. II behaves in a similar manner to the Mk. I and will attack the player by rolling into them. However, if the player jumps or rolls into the Roller, they will not be harmed and the Roller will be bounced back, after which it will briefly pop open its body. This is when it is vulnerable and can be destroyed by any attack while it is standing still.
Sonic the Comic
In the Sonic the Comic series published by Fleetway Editions, the Rollers are a part of Dr. Robotnik's Badnik army. They are also among the first generation of Badniks Robotnik produced, making them one of the doctor's oldest troopers. Also, a kindhearted Roller (named, simply, "Badnik") once befriended a young boy named Smokey, who convinced Sonic to spare it.
Adventures of Sonic the Hedgehog
In the Adventures of Sonic the Hedgehog television series, Roller has a more humanoid design and wears a business suit. Also, instead of curling into a ball, he turns into a bowling ball. In this media, Roller and his partner Ball Hog were a part of Dr. Robotnik's Or Else Protection Service, who bullied Mobians into paying them to not destroy their business, but they were destroyed by Sonic. Later, Tails converted their remains into a waiter for Bert's Diner.