The Teacher
Scholars have said that whoever sees themselves becoming a teacher, the interpretation depends on the dreamer's situation and what befits them from the qualities of educators. The unknown teacher in some interpretations may refer to Allah, based on the Quranic verse {Ar-Rahman taught the Quran}, as He is the teacher of all creation.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam