What Is He: Ian

"I wanted to say, No really, and explain how Ian really wasn't a getting-to-know-you type of cat or eve a casual-hello type of cat, more a sort of whirlwind made out of blades."

Ian is a ginger tabby that apeared in Eric Sanderson's house on the second day after he awoke with no memories.  His psychologist, Dr. Randel, tells him

 that she has no notes about Eric ever owning a cat before now. The cat acompanies him on all of his adventures.