The behavior of "cat jumping in the coffin" itself does not have special omen significance. Cats and coffins each carry some symbolic meaning in many cultures and traditions, but there is no fixed interpretation of them combined.

First, cats are viewed in many cultures as mysterious, flexible and independent animals. Some people believe that cats bring good luck, while others may believe that cats are a symbol of bad luck. However, these ideas often relate to specific behaviors or states of cats rather than their interactions with specific objects (such as coffins).

Coffins are often associated with death and funeral rituals, and are therefore considered an unlucky symbol in many cultures. However, this does not mean that every sight of a coffin brings bad luck or misfortune.

The combination of cats and coffins, that is, "cat jumping on the coffin", may be just an accidental event and has no specific omen meaning. Under no circumstances should we be overly superstitious or rely on these ideas that have no scientific basis.