Sillouhettes of Phobos (a misspelling of Silhouettes of Phobos) is an Ultimate Doom replacement mod of four levels, created by Michael Lundy and released in November 1995. It consists of four spacious levels, the first three replacing the respective maps from Knee-Deep in the Dead, and the last bonus map taking up the E4M1 slot.
- E1M1: "Sinister" by Bobby Prince
- E1M2: "The End of DOOM" by Bobby Prince
- E1M3: "Demons On The Prey" by Bobby Prince
- E4M1: no change