Syrixis, Death’s Herald

Flying, Menace, Deathtouch, Intimidate,
Trample, Infect (This creature deals damage to
creatures in the form of -1/-1 counters and to
players in the form of poison counters)
{b/g}: Target creature under your control
gains infect until end of turn.
No one likes seeing a guaranteed death at their door,
let alone a dragon. So combining the two would be
your worst nightmare.