health bar for the boss level

yeah I kinda need help with this.

You need to post a link to your game.
Otherwise do something like this.
So what you want is when you jump on him, it subtracts 25 from the 100 health bar.
collision player top — (in) number -25 — (+) number 100 — bar (set at 100)
Then you want a filter here ______________________________^ Less than 1 — destroy