Donald Trump again lashed out at President Barack Obama in a wounded tweet — and he was buried in online mockery.

The president-elect — who will keep using Twitter as “a really exciting part of the job,” according to his press secretary — pulled out his phone Wednesday morning to continue the feud that erupted when Obama suggested he could have beaten Trump.

Doing my best to disregard the many inflammatory President O statements and roadblocks.Thought it was going to be a smooth transition – NOT!

— Donald J. Trump (@realDonaldTrump) December 28, 2016

Twitter users quickly heaped scorn on Trump’s apparent insecurity — and his use of the dated “not” quip popularized by the 1992 movie, “Wayne’s World.”

@realDonaldTrump the 90s called and want their teenage slang back. pic.twitter.com/e3b0wNmTTj

— Adam Mordecai (@advodude) December 28, 2016

.@realDonaldTrump No one says "NOT" anymore. Also avoid "Just sayin", "My bad," and "Where's the beef."

— Shannon Watts (@shannonrwatts) December 28, 2016

@realDonaldTrump You spent years accusing him of being secretly Kenyan.

— Parker Molloy (@ParkerMolloy) December 28, 2016

@realDonaldTrump This is your best?

— Alex Leo (@AlexMLeo) December 28, 2016

@realDonaldTrump If "doing my best to disregard" means "whining like a child on Twitter" — you're doing great! pic.twitter.com/sENPmuoUE1

— jeremy cabo 💚 (@jeremycabo) December 28, 2016

trump's already bored, depressed, lashing out. good thing his presidency is almost over.

— Atrios (@Atrios) December 28, 2016

@realDonaldTrump he made one comment DAYS ago, you keep tweeting! Let it goooooo!

— Jordan Uhl (@JordanUhl) December 28, 2016

@realDonaldTrump you played yourself

— maura quint (@behindyourback) December 28, 2016

Trump's tweets can, in part, be seen as a cry for help from a deeply insecure & troubled man, in desperate need of mental health treatment.

— (Kitten) Caboodle (@Caboodle570) December 28, 2016

@realDonaldTrump do a sike joke next pls

— PFTCommenter (@PFTCommenter) December 28, 2016