Noun: Used primarily in vehicular PvP games such as World of Tanks and War Thunder to describe a weapon system (aircraft, tank, ship ect.) That, when in experienced hands, are wildly effective against new players.
Adjective: "puppy kicking" similar to the term "seal clubbing", is the act of experienced players returning to a lower level/tier to compete with new and unskilled players, usually resulting in extremely disproportionate success for the more experienced player. This strategy is normally frowned upon due to its demotivating nature for new players and *usually* diminished benefits to players at high levels. Although this is not always the case. Certain situations may warrant it.
"The P-36C in War Thunder is a bit of a Puppy Kicker"
"Let's go puppy kicking in the tutorial area"