Idk what's up with Igor/Renfield being affiliated with Peter Lorre. Usually I wouldn't count an Igor type character with a Peter impression as a Peter parody but heres one I'd like to mention:
Igor from Mina And The Count. There's nothing significant about him besides the voice which is a Peter impression done by Jeff Bennett.
Who later reuses the voice for the character of The Chameleon from Tuff Puppy who is an actual peter parody.
I like to imagine all 3 of the Dr. Lorres from Looney Tunes are actually brothers. The one from Birth Of A Notion being the oldest, the one from Hair Raising Hair being the middle child and the one from Back In Action being the baby.
I imagine the other Looney Tunes Lorres being cousins and distant relatives like Hugo, Mr. Sydney, Boxcars, ect.