Mausezahn (German pronunciation: [ˈmaʊ̯zəˌʦaːn], German for "mouse tooth") is a fast network traffic generator written in C which allows the user to craft nearly every possible and "impossible" packet.

Herbert Haas, the original developer of Mausezahn, died on 25 June 2011.

Since version 0.38, Mausezahn offers a multi-threaded mode[3] with Cisco-style command line interface.

Therefore, it is rather less suited for vulnerability audits where additional algorithms are required to detect open ports behind a firewall and to automatically evade intrusion detection systems (IDS).

However, a network administrator could implement audit routines via a script that utilizes Mausezahn for creating the actual packets.