Capricopian — ruling 1

Reselecting which player a creature is attacking ignores all requirements, restrictions, and costs associated with attacking.

Capricopian — ruling 2

Reselecting which player a creature is attacking doesn’t cause “whenever this creature attacks” abilities to trigger.

Capricopian — ruling 3

If you reselect which player an attacking creature is attacking, that creature is still considered to have attacked the player as declared, but it is now attacking the new player.

Capricopian — ruling 4

The player Capricopian is attacking can’t reselect it to attack a planeswalker instead. If Capricopian is attacking a planeswalker, no player may activate its last ability.

Capricopian — ruling 5

The player Capricopian becomes attacking may activate its ability, perhaps sending Capricopian right back towards its original destination.

Capricopian : règles, fonctionnement et interactions (MTG)

Capricopian 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

This creature enters with X +1/+1 counters on it. : Put a +1/+1 counter on this creature, then you may reselect which player this creature is attacking. Only the player this creature is attacking may activate this ability and only during the declare attackers step. (It can't attack its controller.)

How it works : Capricopian

Original English text — Wizards of the Coast / Scryfall

#1April 17, 2020· Wizards of the Coast
Reselecting which player a creature is attacking ignores all requirements, restrictions, and costs associated with attacking.
No other card is named in this ruling.
#2April 17, 2020· Wizards of the Coast
Reselecting which player a creature is attacking doesn’t cause “whenever this creature attacks” abilities to trigger.
No other card is named in this ruling.
#3April 17, 2020· Wizards of the Coast
If you reselect which player an attacking creature is attacking, that creature is still considered to have attacked the player as declared, but it is now attacking the new player.
No other card is named in this ruling.
#4April 17, 2020· Wizards of the Coast
The player Capricopian is attacking can’t reselect it to attack a planeswalker instead. If Capricopian is attacking a planeswalker, no player may activate its last ability.
No other card is named in this ruling.
#5April 17, 2020· Wizards of the Coast
The player Capricopian becomes attacking may activate its ability, perhaps sending Capricopian right back towards its original destination.
No other card is named in this ruling.