Death-Related Prefixes
Prefixes along the lines of Blood-, Bone, Maggot-, and Carrion- are not used in this system. Yew- is acceptable because it also refers to the tree in its entirety, but to name a cat yew’s euphemism, Deathberry, would be unacceptable.
Clans live with death every day, and they have no (canon) culture of worshiping or revering its presence. As predators, they understand that other animals must die for them to survive, and so it is for cats of other Clans as well. Cats of their own Clan must also die in order for younger generations to come to power, but this has always been shown as occasion for mourning rather than celebration. Clan cats resist death for all they are worth, and in fact one could make a case that Clans were established to prevent high mortality by providing assistance to one another. In light of this, to name a newborn kit after an aspect of or related to death would seem unlucky at best, cruel at worst.
After much thought, I have also excluded Tick- and Mosquito- because these are bloodsucking parasites on cats, and I feel they would be considered cowardly names by a warrior culture. (A fox, at least, will fight you to the death.)