Benjamin Mattern is a Brazilian jiu-jitsu black belt based in Heidelberg, Germany, affiliated with Team Choco Heidelberg. His public training record lists Thomas Stoll as his black-belt promoting instructor in December 2025, following earlier brown- and purple-belt promotions at Team Choco. BJJ Globetrotters lists him among the instructors for its 2027 Zen Camp. His documented background connects the Heidelberg training community with international camp teaching.
