Duracell bunny

Etymology
From the Duracell Bunny, a pink rabbit toy character from the advertising campaign of Duracell, used to demonstrate the longevity of the batteries.

Noun

 * 1) A person who seems to have limitless energy and endurance.
 * 2) * 2010 April 4, Jonathan Northcroft in The Timesonline, Manchester United player ratings
 * Patrice Evra — 7. France’s own Duracell bunny was the only United player who never seemed tired. Defended well and was a valuable attacking outlet.
 * 1) * 2010 April 25, Julian Glover in The Guardian Online, David Cameron Profile
 * Conservative leader is a stress-tested Duracell bunny with the capacity to make any crisis seem reasonable, or so his friends say.