Where does “ꦲꦤ꧀ꦝ” come from?

ꦲꦤ꧀ꦝ (Javanese) comes from Old Javanese aṇḍa, from Sanskrit अण्ड — egg; testicle; scrotum.

ꦲꦤ꧀ꦝ (Javanese): ladder