The Super Smash Bros Ultimate Piranha Plant add-on’s release date has been pinned down a bit. While we still don’t know exactly when the character will appear, we do know that the character will be released in February 2019. This was revealed as a news story in the Nintendo Switch news feed and as an update sent out in-game.
As a reminder, the Piranha Plant is a free DLC character for people who have purchased Super Smash Bros. Ultimate by January 31, 2019. However, it is only free for a limited time. The code for it is distributed by email to the account your Nintendo Network ID is connected to, and Nintendo Support noted that Gmail users may find the email in the Promotions folder.
If you miss out on getting the free Piranha Plant, it will eventually be available for purchase. However, Nintendo has noted that it will be sold outside of the Fighters Pass that will include Persona 5‘s Joker and four other characters.
Super Smash Bros. Ultimate is available for the Nintendo Switch.