Let me know if I missed any.

Since the election, Trump has attacked the following on Twitter:

• People protesting him
• The New York Times
• The cast of "Hamilton"
• Saturday Night Live
• Jill Stein
• CNN
• China
• The "unfair and dishonest" media
• Boeing
• United Steelworkers
• NBC Nightly News
• Lockheed Martin
• Vanity Fair
• Bill Clinton
• Hillary Clinton
• The United Nations
• President Barack Obama
• North Korea
• General Motors
• Congress
• The Affordable Care Act
• Senator Chuck Schumer
• Toyota
• Arnold Schwarzenegger
• Meryl Streep
• Buzzfeed
• Intelligence agencies
• Congressman John Lewis

Since his inauguration, Trump has attacked the following on Twitter:

• The people at the Jan 21st worldwide marches for Women’s Rights
• CNN (again and repeatedly)
• Chicago
• Chelsea Manning
• Mexico
• The New York Times (again and repeatedly)
• The Washington Post
• Senator John McCain (multiple times)
• Senator Lindsey Graham
• Senator Chuck Schumer (again)
• The Democrats
• House Minority Leader Nancy Pelosi
• Australia
• University of California, Berkeley
• Iran
• Arnold Schwarzenegger (again)
• People protesting him (again and repeatedly)
• U.S. District Judge James L. Robart
• The courts blocking his executive order on banning Muslims from seven countries
• ABC News
• The "unfair and dishonest” media (again and repeatedly)
• Politics
• Nordstrom
• Senator Richard Blumenthal
• Chris Cuomo

Notably missing from this list:

• Vladimir Putin
• The white guy that killed six Muslims in a Quebec mosque