Are the Deadlights Its True Form?

The Deadlights are the true form of Pennywise/IT. The Deadlights are orange writhing lights that exist in Todash Darkness. ... Pennywise's spider form, the form that he doesn't pick from the victim's mind, is the closest our minds can come to comprehending the deadlights without going insane.

What exactly are the Deadlights?

In the 1986 book, the deadlights are a sea of destructive orange lights that drives most humans insane upon sight or ultimately kills them. It uses them to paralyze his victims before he completely consumes them. They are also probably responsible for the orange glow in Pennywise's eyes.

What is the true form of Pennywise?

In the novel, It's origins are nebulous. He took the form of a clown most frequently, Mr. Bob Gray or Pennywise, but his true form is an ancient eldritch entity from another universe who landed in the town that would become Derry by way of an asteroid and first awoke in 1715.