Corpse Augur — ruling 1

You choose the target player as the ability goes on the stack, but you determine the value of X as that ability resolves. If you target yourself and Corpse Augur is still in the graveyard, its ability will count itself.

Corpse Augur : règles, fonctionnement et interactions (MTG)

Corpse Augur is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

When this creature dies, you draw X cards and you lose X life, where X is the number of creature cards in target player's graveyard.

How it works : Corpse Augur

Original English text — Wizards of the Coast / Scryfall

#1November 4, 2015· Wizards of the Coast
You choose the target player as the ability goes on the stack, but you determine the value of X as that ability resolves. If you target yourself and Corpse Augur is still in the graveyard, its ability will count itself.
No other card is named in this ruling.