Changkey

Changkey (チャンキー), localized as Tackle Fire in some English sources, is a small robot from the original Mega Man series that is covered by flames. It appears by itself or is spawned by other enemies.

Mega Man
Changkey appears from the lava in Fire Man's stage in sets of three.

Mega Man Powered Up
Besides their appearance in Fire Man's stage, they also appear in Oil Man's stage as projectiles from Hothead, where they can ignite oil.

Mega Man 2
Changkey appears as a projectile from the enemy Changkey Maker, which creates and throws them from its head.

Mega Man 9
Changkey appears as part of the Changkey Dragon.

Mega Man 10
Changkeys appear in Solar Man's stage, Wily Castle stage 4 and Special Stage 1, where four of them fly in parabolic arcs from one turret to another and back.

Mega Man: Dr. Wily's Revenge
Changkey appears in Fire Man's stage, were they are invincible and just appear falling into lava.

They also appear as projectiles from Changkey Maker.

Mega Man: The Wily Wars
Changkey appears in the first part of the Wily Tower.

Other appearances

 * Changkey appeared in Battle Memory from Rockman Xover.
 * Changkey appeared as a projectile from Changkey Maker in Rockman Go Go!.
 * Changkey is an obstacle in Rockman Panic Fire.

Rockman Complete Works data
火をまとった小型ロボット. 破壊してすすもう.

Mega Man Legacy Collection translation:

A small robot clad in flame. Take it out, and move on.

Changkey R
Changkey R (チャンキーＲ) is a revised version of Changkey. Not much has changed about it compared to its first appearance, with three of them appearing from a fiery pit and falling. They only appear in one section from the Opening Stage of Mega Man & Bass.

Changkey (Mega Man Network Transmission)
Changkey appears as a virus in Mega Man Network Transmission. They only show up in the area "Net on Fire." When they shoot up from the lava, they float down and towards their target.

Other media
Changkey has short appearances in the Mega Man comic series, in Mega Man Megamix, in the Rockman manga, and in the Rockman World manga.

Trivia

 * Changekey is similar to the Lava Bubble from the Mario universe as both are fireball-like enemies that pop up and down from lava-filled pits.
 * Changkey was named after the nickname of a Capcom employee.