Madmole

Madmole, known as Mogu-Mogu (モグモグ) in Japan, is a mole-type Badnik created by Dr. Robotnik. It first appears in Sonic & Knuckles, where these blue and grey colored moles have yellow helmets on their head and weird harpoon hands.

Sonic & Knuckles
In Sonic & Knuckles, Madmoles are great nuisances, as featured at Mushroom Hill Zone. When approached, Madmole will pop out of his "hole", and throw mushrooms at the player. If the player is hit, the mushroom will not do any harm, but it will throw the player away until it bounces away. The player can easily defeat them with Spin Jump.

Sonic Generations
Madmole makes a reappearance at Mushroom Hill Zone, that is featured in Nintendo 3DS version of Sonic Generations. In the game, their behavior has not changed and in classic act of the Zone, they can be found at same spots like in their first appearance.

Sonic Lost World
Madmoles makes another appearance in Sonic Lost World. During the game, it turns out that Badniks, including Madmoles, got hijacked by the Deadly Six. In the game, they are able to find from Silent Forest, where they are hiding on groups at small burrows and will eventually pop out and try throw mushrooms into player once he/she is nearby. The player can easily defeat them by performing Homing Attack on them.

Trivia

 * After completing Mushroom Hill Zone Act Two with point results in Sonic & Kncukles, as the Flying Battery flies above the player and Robotnik fleeing there, a recolored Madmole can be noticed as it is piloting the ship. However as the player has enter to Flying Battery Zone, these Madmoles are not featured as enemies or don't appear in the zone at all.