No, German citizens can enter Tunisia without a visa.

For a stay of up to 90 days, a visa to Tunisia for citizens of Germany residing in Russia is not needed. Important: the validity of the passport must be at least 3 months from the date of entry into the country. A tourist voucher is desirable as a reason to enter the country (of course, if it's a tourist trip).

The stamp on entry is placed after the immigration card is filled upon arrival for free. Please note that the immigration card consists of two parts, separated by perforations. At the airport of Tunisia, one part of the passport control comes off, the second part must be kept until the end of the trip and presented at departure from the country.