Besides the "Soothsayer" in Act 1 scene 2, what else could be considered a bad omen?
In Act II, Scene 2, Caesar's wife Calpurnia begs him not to go to the Senate House because she has dreamt that she saw his statue spouting blood. She also tells him:
There is one within,
Besides the things that we have heard and seen,
Recounts most horrid sights seen by the watch.
A lioness hath whelped in the streets,
And graves have yawned and yielded up their dead.
Fierce fiery warriors fight upon the clouds,
In ranks and squadrons and right form of war,
Which drizzzled blood upon the Capitol.
The noise of battle hurtled in the air.
Horses do neigh, and dying men did groan,
And ghosts did shriek andd squeal about the streets.
A servant tells Caesar that the augurers have found bad signs when making a sacrifice:
They would not have you to stir forth toay.
Plucking the entrails of an offering forth,
They could not find a heart within the beast.
Caesar ignores the warnings. A short time later he encounters the Soothsayer again and says:
The Ides of March are come
To which the Soothsayer replies:
Ay, Caesar, but not gone.
At that point (III.3) Artemidorus attempts to give Caesar a letter specifically warning him against the plotters he is with, but Caesar refuses to read it in spite of Artemidorus's insistence. Then he is surrounded by the assassins and stabbed to death.