Madrat was a Markalian who visited Deep Space 9 in 2374.

When in Quark's, he attempted to stop Molly O'Brien after she had escaped from a holosuite, but she stabbed him with a broken bottle. He was taken to the infirmary, where he was treated for his wounds by Doctor Bashir. He later filed charges against Molly for assault with a deadly weapon. (DS9: "Time's Orphan")

Madrat was played by stunt actor Tom Morga who received no credit for this appearance.
Madrat's name was not mentioned in dialogue, but is taken from the script.
Sisko identified him as Tarkalean, but he bears no similarities to the Tarkaleans seen later in ENT: "Regeneration". His make-up is that of a Markalian, which is why he is identified as such here. The Star Trek Encyclopedia (4th ed., vol. 2, p. 10) identified Madrat as a Tarkalean national, implying that while he might not look like a Tarkalean, he might be a citizen of their nation.