Using a username sniper is a high-risk activity that often leads to account termination.
Once available, the tool uses an account token to instantly update the username. Risks and Terms of Service (ToS) Username Sniper Discord
A Discord username sniper is an automated script or bot that monitors the availability of specific usernames. When a user changes their handle or deletes an account, their old username eventually becomes available for others to claim. A sniper bot "snipes" this name by sending a high-speed request to Discord’s API to register it before any human can react. Common targets for snipers include: Using a username sniper is a high-risk activity
If you are planning to change your username and want to avoid being sniped: Do NOT change usernames - Discord Support Username Sniper Discord