Its last appearance was in 2020. as the dancing clown now he is gone for good or is he ?

Tim curry is the actor of IT in 1995, he was born 19 April 1946  age (75 years) 

IT is not a clown he is a god in a mask to hide his true form  his weaknesses are courage and heart 

The Clown from IT largely remains a mystery to The Losers Club (how the kids from IT refer to their gang) as well as audience members unfamiliar with King's original 1986 Stephen King novel. 2019's IT: chapter 2 built out the Pennywise the clown origin story. The sequel, set 27 years later and starring James McAvoy and Jessica Chastain alongside Skarsgård, sees the Losers Club kids return to Derry as adults. They defeat Pennywise a second time, but on this occasion, they learn much more about the creature's true nature. The original IT novel by Stephen King also explains much more about Pennywise, as is often the case when a book is adapted into a film. Below is the origin of Pennywise from the IT movie explained

Pennywise the Clown is not a clown at all. The Pennywise the clown origin story sees an ancient, evil being that is perhaps as old as the universe itself. In the novel, however, the entity IT/Pennywise has a real name — Bob Gray.

b Gray isn't human, however, and shares the same origin as IT. The human name was a touch of surrealism on King's part, a juxtaposition to the long unpronounceable names of similar cosmic beings from Lovecraft novels like Nyarlathotep or Ghatanothoa. It's a trick King has mirrored in other novels. The films chose to drop this to an extent, as it doesn't translate as well to screens (it goes from unsettling to just plain confusing