Grounder

Grounder (ハンドリル) is a mole-type badnik created by Doctor Robotnik, that first appeared in Sonic the Hedgehog 2. Grounders are successors of Burrobots from the original Sonic the Hedgehog in terms of its design and attack pattern. As well as a nose drill, like Burrobot, it also has a drill at the end of each arm.

Sonic the Hedgehog 2
Grounders made their first appearance in Sonic the Hedgehog 2, as these badniks can be found at Aquatic Ruin Zone. It appeared only in the Aquatic Ruin Zone. Grounders usually move around back and forth on the ground or underwater while its drill hands and nose are spinning. Though not dangerous on their own, Grounders are positioned in very strategic places such at the top of paths above the player to block his/hers way or be hidden in the walls. When hidden inside walls, Grounders will drill out from walls when the player passes them and suddenly hit the player with drill hands and nose. The player can still easily destroy Grounders by performing Spin Attack or Spin Jumping on it.

Sonic the Hedgehog Pocket Adventure
Grounder later made another appearance in Sonic the Hedgehog Pocket Adventure, as being featured at Aquatic Relix Zone, which is similiar to Aquatic Ruin Zone while having same gimmicks and badniks. Grounders have exact same attack pattern from Sonic the Hedgehog 2.

Physical Appearance
As being successors of Burrobots, Grounder is similar type of badnik, although being more bulky looking. Grounder has red colored metallic body, that moves with two continuous tracks, as one on each side. Grounder round head has two grey bolts (purpose of being eyes), a white aerial on the back of the head and large drill bit bottom between bolts. In between head and body goes yellow line. Lower, broad body has blue button, each shoulder is round shaped and left one has early Eggman Empire symbol in it, while each hand has set slightly smaller drill pit.

Attack Patterns
Much like the Burrobots, the Grounder badniks mainly attack the target by breaking through walls and launching a surprise attack. It uses both drill pits on its head and arms to drill through the walls and hitting its target. On the other side, Grounders are like many other badniks that move backward and forward on the land or underwater.

Sonic the Hedgehog 2 Strategy Guide
Different coloring of Grounders are seen drilling in small comics of Japanese Sonic the Hedgehog 2 strategy guide, which tells loosely the original Japanese storyline of the game. There are purple and green colored Grounders, while Eggman is searching Chaos Emeralds. Only for while, Grounders are quickly destroyed by Sonic.

Sonic the Hedgehog Yearbook 1992
The large variation of Grounder has appeared in Sonic the Hedgehog Yearbook 1992' story "Big Trouble", which has also been created by Doctor Robotnik. Sonic and Tails encounter large badnik as it burst through the wall. As duo tries to damage the badnik with Spin Attack, it only bounce off of its shell harmlessly. Robotnik announces in Eggmobile with hammer extension to Sonic and Tails, that it is the first of a new giant badniks whose size and strength will assure his conquest of taking over Mobius where others failed.

Tails wonders if they have to fall back against Grounder, but Sonic demands to not so. With a little lateral thinking, Sonic and Tails then starts jumping up to higher levels, as they are perched atop a column high above the Grounder. They then both leap down and perform the Spin Attack to its head, thus destroying it. It turns out that three animals were needed to power this Grounder's organic batteries, and they are all freed.

Sonic the Comic
In Fleetway's Sonic the Comic, Grounder was part of Robotnik's badnik army. During his initial reign over Mobius, they were only utilised on one occasion, helping Robotnik break into Sonic's Secret Underground Base (Doctor Ovi Kintobor's old laboratory) along with his Squeeze Tag Machine and several Crawlton and Tunnelbot models. They succeeded in breaking into the Freedom Fighters' base, but were thwarted when Knuckles the Echidna arrived to help. The battle was taken outside where Knuckles, Sonic the Hedgehog and Johnny Lightfoot finished them off.

Adventures of Sonic the Hedgehog
In Adventures of Sonic the Hedgehog, a single green Grounder was one of the main antagonists of the show. Grounder is one of the main henchmen of Doctor Ivo Robotnik. Together with Scratch he was created to be a part of the Super Special Sonic Search and Smash Squad, whose job it is to eliminate Sonic the Hedgehog and aid his creator in his various schemes. However, Grounder is incredibly stupid and gullible, and often ends up causing his team and Robotnik more trouble when Sonic is trying to foil Robotnik's plans.

This variation of Grounder also appears in Dr. Robotnik's Mean Bean Machine, Archie's Sonic the Hedgehog comics and as minor character at Sonic Live that was held in Sydney.

Trivia

 * In the Christian Whitehead-produced 2013 mobile re-release of Sonic the Hedgehog 2, a green Grounder appears as a new object in Debug Mode.
 * Grounder is one of the few badniks in Sonic the Hedgehog 2 that features an early version of the Eggman Empire symbol, which can be seen on its shoulder armor.