How does this happen?

[Catalytic]

PvP battles, which I already hate, make no frickin' sense.

DM rabbit, S/S, speed is 357. Crow, P/S, speed is 289. Crow used Darkness. Why did the Crow go first?

This was the first round of a PVP battle, so it's not like I swapped in the DM Rabbit and lost part of a turn.

[Waflob]

Flying pets get a speed buff above 50% life (their class bonus).
(or did you mean something else?)

[Catalytic]

Nope, that completely explains it, thank you!