During Chapter 93: "Pochi", after defeating Royal Ripper and saving Tareo, Garou comes face to face with Overgrown Rover. Fortunately, the two of them were able to escape from it, sneaking away, only to be caught off-guard by Demon level Monsters Showerhead, Super Mouse, and Unihorn. During their fight, the three Monsters band together in order to form a combo attack, the Triple-Demon High-Speed Shish Kebab, a combination of Shower Head's Jet Water Flow, Unihorn's Killest Form, and Super Mouse's "mega-muscles", creating a blinding fast projectile attack which Garou likens to Stinger's Gigantic Drill Stinger, before amptly deflecting it, commenting that "to my eyes, it was barely moving.
According to this study from, supposedly, the early 2000s, the speed of a water jet is 2,500 ft/s or 762 m/s. Using the formula implemented on numerous blogs, most notably "A Compilation of Sonic Feats", "most notably" because I wrote it, (real speed of reference object / apparent speed of reference object) * apparent speed of object of interest = real speed of object of interest).
- Real speed of reference object: 762 m/s
- Apparent speed of reference object: 0.001 m/s (snail's speed)
- Apparent speed of object of interest:
10.03 m/s5 m/s (762 / 0.001) * 10.03 = 7642860 m/s (2.5% lightspeed) = Sub-Relativistic
(762 / 0.001) * 5 = 3810000 m/s (1.2% lightspeed) = Sub-Relativistic
Using an end of Mach 3 amplifies this to 5145000 m/s, but at the end of the day, that is still Sub-Relativistic, even smaller than the original result.
This isn't even taking into account that the attack would likely be faster than a basic water jet, considering it's propelled by both Super Mouse's superhuman strength (he has Class 25 Lifting Strength, by the way) and Showerhead's Jet Water Flow.
The reason that I used Peak Human speed for the apparent speed of object of interest instead of Average Human speed is because, while they yield similar results, Peak Human is more in-line with the depiction of his movements, with his arm still obscured by motion blur by the time the attack went soaring into the background, indicating that he was obviously moving faster than the average human, but to avoid inflated results, we'll keep it at Peak Human.
You could argue that this is inapplicable, because Garou was simply bluffing about the attack being practically stationary to him, but he has no reason to bluff or lie to these Demon level Threats. We see Garou casually redirecting their attack elsewhere, and then he goes on to state "That was no big deal", further driving home the fact that this attack meant nothing to him. In fact, in the page before Garou redirects their attacks, he was completely stationary, only choosing to act at the last moment, which he does so with ease.
Half-Monster Garou's casual combat speed: 3810000 m/s (Sub-Relativistic)