The Crawlton's design is an upgrade of the original Caterkiller Badnik. Its body is much longer than that of its predecessor, having between eight and ten body segments, all of which have metal spikes on their sides. Its head has a pair of radio antennae for hearing, and a pair of sharp mandibles in place of a mouth.
Crawltons are capable of tunneling through soil and rock and can strike out at targets quite quickly. When a target is near, they will spring out and extend their bodies to reach and snap at their would-be victim.
Sonic the Hedgehog 2
In their first appearance, Crawltons are encountered in the Mystic Cave Zone. They will hide within the terrain itself, lunging out at the player when they are within range. Despite their spiked body segments, the player cannot actually make contact with the Crawlton's body, only its head. So long as the player is spinning, they cannot be harmed if the Crawlton's head touches them and will destroy the Crawlton on contact.
Sonic Lost World
In both versions of Sonic Lost World, the Crawltons are featured in Desert Ruins, Tropical Coast and Frozen Factory. During the game, all the Badniks, the Crawltons included, got hijacked by the Deadly Six. In the Wii U version of the game, they serve as normal enemies that hide in small bushes in the desert, and will most of the time attack the player in groups. In gameplay, they burrow across the desert sands with their heads above the surface and when the player gets close to them, they will pop out the sand in a swift motion to damage Sonic. Additionally, the Crawltons have a noticeably longer attack range than in Sonic the Hedgehog 2.
In the Nintendo 3DS version of the game, Crawltons are larger enemies which can take multiple hits. These Crawltons must be destroyed for the player to progress in the Zone, similar to Sandworms. In battle, they hide in a shadow on the ground from where they will pop out of to attack the player, for then to retract back into and repeat the pattern. To defeat this Crawlton, stun it with a Somersault Kick and then attack the glowing weak spot on it with the Homing Attack three times (or less with a charged-up Focused Homing Attack). Before the last hit, the Crawltons will overheat and start swinging their body swing around.
Sonic the Comic
In the Sonic the Comic series published by Fleetway Editions, the Crawltons are a part of Dr. Robotnik's Badnik army. Depending on the artist, the Crawltons' design would be altered slightly various times. They were one of the more recurring Badnik types early on in the comics, but appeared more scarcely as time went on.
Sonic the Hedgehog: The Movie
The Crawlton was one of the few Badniks to appear in the Sonic the Hedgehog OVA. When Sonic and Tails ventured into the Land of Darkness to shut down the Egg Generator in Eggmanland, they encountered a Crawlton during their journey. This Crawlton was much longer than its game counterpart and was capable of flight. It attacked Sonic head on, but Sonic's Spin Attack smashed it to pieces.