Disney's Marvel unit has filed five lawsuits in hopes of retaining full control and ownership of Avengers characters including Iron Man, Spider-Man, Dr. Strange, Ant-Man, Hawkeye, Black Widow, Falcon, Thor, and others. News of these filings was first reported by The New York Times.

The litigation is a counter move after heirs of several Marvel authors filed dozens of termination notices with the U.S. Copyright Office, seeking to end Marvel's licenses to the characters. However, Marvel argues that the characters were created under "work for hire" arrangements, meaning that the heirs would have no valid claim to the copyrights.

In the filing, Marvel draws a parallel to a case involving Jack Kirby, who co-created The X-Men, Thor, and Iron Man. Kirby's heirs similarly sought to reclaim copyright to his creations, but the federal courts sided with Marvel, finding that the characters were created under work-for-hire arrangements. Marvel's lawyers, led by Daniel Petrocelli, say these cases present "virtually identical circumstances."