Crazyhouse is a chess varient.
These are the rules
https://en.wikipedia.org/wiki/Crazyhouse
Hacking and Cheating on Chess.com Server

Looks like you accidentally played a game of crazyhouse. In crazyhouse, when you capture a piece, it becomes yours and, for your move, you can drop it anywhere it could legally go (i.e. no pawns on the back rank).
In crazyhouse, it's quite common to have three or even four knights or bishops. Or to have nine or ten pawns.

Looks like you accidentally played a game of crazyhouse. In crazyhouse, when you capture a piece, it becomes yours and, for your move, you can drop it anywhere it could legally go (i.e. no pawns on the back rank).
In crazyhouse, it's quite common to have three or even four knights or bishops. Or to have nine or ten pawns.
exactly thats what happened to me,

You're not the first to accidentally play crazyhouse and think your opponent was cheating.
In one of the live crazyhouse tourneys, in the third round, my opponent accused me of cheating for having nine pawns. I wondered how he got to the third round without figuring out what was going on.
After the tournament was complete, I checked his games from the first two rounds. In the first round, neither player made a single drop; they played it as a normal chess game, and even got into an endgame. In the second, his opponent only did one or two drops, and he probably never noticed.
After the tournament, I sent him a message to explain what crazyhouse was.

You're not the first to accidentally play crazyhouse and think your opponent was cheating.
In one of the live crazyhouse tourneys, in the third round, my opponent accused me of cheating for having nine pawns. I wondered how he got to the third round without figuring out what was going on.
After the tournament was complete, I checked his games from the first two rounds. In the first round, neither player made a single drop; they played it as a normal chess game, and even got into an endgame. In the second, his opponent only did one or two drops, and he probably never noticed.
After the tournament, I sent him a message to explain what crazyhouse was.
hahaha
luckly it happened to me in 1st game,,
thank u very much for detailed clearance
Just before I was stunned by a sort of Hacking cheat in a game vs [Do not name and shame - Mod.] . This is sort of hacking ,my opponent was having extra pieces likes 3 knights and 3 rooks right from beginning, here is the screen shot.