ALWAYS clap to pick up bananas you get a TON more at the end if you do.

To get to the final boss, Ghastly King, clear Star Fruit Kingdom and collect 51 Crests. This boss is similar to Cactus King but has a spinning kick move, which you can grab if you get beneath him.

Turet tusk is pretty easy.First "CLAP!" to pick up a pinapple grenade,then "CLAP!"
again when he sucks throgh his trunk/canon (If the trunk/canon is pointed to high, ,jump and then "CLAP!") if he sucks the pinapple grenade into his trunk/canonAfter that his heart should appear along with 4 pinapple grenades.Then go to where the hill slopes down and "CLAP!"8 times (If you have enough time throw the one at the top of the hill too).Repeat proses till he goes down.
note: I accidentally put this in hints too.