Mix agar-agar, milk, sugar, and cocoa powder, bring to boil while keep stirring. Pour into a mold (rectangular/loaf shape preferably) and let harden in fridge
Once harden, prepare jell-o per box (1 cup hot water, 1 c cold water)
Using ice cream scoop or round measurement spoon or even olive spoon, scoop agar-agar as shown (make holes/balls), putting aside the balls for later
Fill the whole with jell-o as shown on picture, and let harden in fridge
Once harden, place the previous balls of agar-agar on top of jell-o, then pour the rest of jell-o into the mold
Let harden in fridge, unmold pudding, slice, and serve.
Enjoy~