Odd question but... What irl instrument most closely resembles the Fipple Flute?

besides gaming I'm a fairly skilled ocarinist and I'm wondering, is there an irl instrument that resembles the Envoy's fipple flute in form and playing method? I'm immensely curious as my brother has recently informed me he wants to learn a woodwind as well. i could teach him the ocarina but if I could find something similar to the ingame flute he'd likely find it very cool.

alternatively what range of ocarina would be that deeper tone like the fipple flute. my ocarinas are tenor c and a bit too shrill for him. (hurts his ears)