Necroscepter is the best possible relic there is for a Zombie Deck. It's unlimited use, while bag of cats is limited. Also zombies come with Leech and imps do not. But hey, you should play however you like, just do what is fun for you. There is a case for Bag of Cats in decks focused on OTK through Corpse Explosion.

You can get the deck code from the game client in the deck window on the top right corner. You can also check you match history in GU Decks and copy the deck code from there.

Some people also take screenshots of the decklist to add to their posts as a visual aid, alongside the deck code itself. That is cool too.