A robot lures a giant monster into the ocean by navigating a burning boat out to sea. Their body is destroyed, but their CPU was salvaged and technically lives on at the end of the show.
There is an episode where the characters believe that a hotel is haunted by a ghost, but it's later found out that the ghost is actually a hologram of a prerecorded message from a former zookeeper.
"Friends" are animals which have taken on a human form due to exposure to the mysterious substance Sandstar.
When Friend's life ends, they do not truly "die", but instead they revert to their original animal form. They also lose any memories they have from their time as a Friend.
In episode 1, Serval hears a brief yell, and because of this, she suspects that a Friend was attacked by an enemy Cerulean/Cellien. The Friend is entirely off-screen, and the viewer does not find out anything more about her in that episode.
In episode 12, we see an aardwolf briefly - a normal animal aardwolf, not a Friend. This is actually the Friend who yelled in episode 1, though she's no longer a Friend, indicating that she did not "survive" the attack and reverted to animal form. In her animal form, she is alive and well.
There is a running gag where Kaban is surprised and yells "don't eat me," but no actual cannibalism occurs, and we're told and shown multiple times that Friends do not even eat non-Friend animals once they become Friends, much less each other.