The Energy Tank, or E-Tank for short, is a staple item of the Mega Man series that appears in Super Smash Flash 2. It heals all of the character's damage, no matter how high. When this item is grabbed, the character will hold it over its head until fully healed; naturally, the player is extremely vulnerable while healing, and one hit of any strength will cause the E-Tank to disappear. The design of SSF2's E-Tank comes from Mega Man 2.
The E-Tank was the first kind of tank to ever appear in the Mega Man games. It first appeared in Mega Man 2, and since then has been present in almost all games from the original Mega Man series. It fully recovers the health of the user, doing exactly the same in SSF2. Because of that, E-Tanks are the second rarest and hardest item to be get, just after the more useful 1-Up. E-Tanks can be stocked in the Mega Man games, the maximum number of E-Tanks that could be carried was initially four and was increased to nine for Mega Man 3 to Mega Man 6, but was reduced back to four for the Game Boy games and Mega Man 7. It returned to nine for Mega Man 9 and 10. The E-Tank also appears in the Mega Man ZX series, where only one can be carried at a time.