Even the strongest of Jedi Masters need guidance sometimes, and fortunately for Luke Skywalker in Star Wars: The Last Jedi, he got some thanks to a visit from his deceased mentor, Yoda. As Luke was getting ready to burn down the tree containing all the sacred Jedi texts, the Force Ghost of the little, green whatever-he-is appeared to offer Luke some much-needed words of wisdom. Rather than create Yoda using CGI as was done in the Prequels, The Last Jedi instead chose to harken back to the old days and bring him back via puppetry. So when the time came for Mark Hamill to act across the Yoda puppet, a lot of members of the crew turned up to watch the sequence unfold. Creature and droid FX supervisor Neil Scanlan recalled:
It was unbelievable when we shot that sequence. The tree was on fire, I turned around, and behind me there must've been a 60-strong audience of people out on a location who would not normally have bothered to stand in the cold weather. It was totally silent, and all we could hear was Yoda and Frank Oz and Mark Hamill.
Since director Rian Johnson felt it wouldn't have been as emotionally resonant to have Luke Skywalker interacting with Force Ghost Obi-Wan Kenobi in The Last Jedi since it would be Ewan McGregor playing the character rather than the late Alec Guinness, that meant it was up to Force Ghost Yoda to talk some sense into Luke after Rey departed Ahch-To. For the moviegoers who hadn't heard the rumours about Yoda coming back for The Last Jedi, that moment was undoubtedly a big surprise, but as Scanlan added while speaking with HuffPost, shooting the Luke and Yoda reunion was "as iconic" as he hoped it would be.
Channeling the comical side of his personality last seen in The Empire Strikes Back with the enlightened perspective we've seen from him in all his previous appearances, Yoda reminded Luke Skywalker about how a Jedi must be sure of his/her path. However, when Luke decided not to destroy the Jedi texts, Yoda summoned a bolt of Force lightning and set the tree ablaze himself. When Luke questioned why Yoda carried out the deed, the little green friend stated that it was up to Jedi themselves to pass along their knowledge and continue their ways, not books. With Luke having passed on, it's up to Rey to keep the Jedi going, though if Force Ghost Luke visits her in Episode IX, perhaps he can bring Yoda with him.
The franchise set in a galaxy far, far away will continue with the release of Solo: A Star Wars Story on May 25, 2018, and the current trilogy will conclude when Episode IX hits theatres on December 20, 2019.