The title is not clear, I know. Let me explain what I mean:
First column has td elements which have varying rowspans. What I want is to keep the td text in first column 'fixed' at the top while scrolling down. But only as long as the rest of the td elements in the remaining columns are in scope. Once all the rows (which the first column cell is spanning) is out of table view, the td element should scroll out of the view and the next td should now start fixing.
After Scrolling a bit:
And after All the animal rows are scrolled out, the fixed 'Animal' td would also go up and then 'Cars' would be fixed and then Hats would be fixed like this: