"Just tried watching Saturday Night Live - unwatchable! Totally biased, not funny and the Baldwin impersonation just can't get any worse. Sad," tweeted the president-elect shortly after midnight.
Baldwin shot back about 15 minutes later, tweeting, "Release your tax returns and I'll stop. Ha."
Last night's episode, which featured "SNL" cast member Kate McKinnon as Trump senior adviser Kellyanne Conway, poked fun at Trump's use of Twitter, his campaign promises and vanity.
The cold open began with a high school student in a classroom sharing that Trump retweeted him -- in reality, Trump did retweet a 16-year-old named Seth who slammed CNN's coverage of Trump.
McKinnon's Conway says Trump tweets so much "to distract the media from his business conflicts and all the very scary people in his cabinet."
Baldwin’s Trump responds, "Actually that's not why I do it. I do it because my brain is bad."
Then, taking a jab at Trump's campaign promises, the fictitious Trump says, "And next I'm going to do what I promised my whole campaign ... I am going to build that swamp."
McKinnon's belwildered Conway asks, "Don't you mean drain the swamp and build the wall?"
Responds Baldwin's Trump: "No, that's too many things. Just smush them together. Smush!"
Trump senior counselor Stephen Bannon was also ridiculed during the cold open.
"Where is my chief strategist Steve Bannon? I can't start without Steve Bannon," says Baldwin's Trump.
Who walks in? An actor in a grim reaper costume.
And in a nod to Trump's vanity, something appears to grab the attention of Baldwin's Trump off-camera, and he asks McKinnon's Conway, "Wait is that the picture of me I hate, the one the press is using where I look so ugly?"
Says McKinnon's dumbfounded Conway: "No, that's just a plate of mashed potatoes."