I'm surprised no-one has posted this tentacle type reference chart yet-
rule34.xxx/index.php?page=post&s=view&id=3835638

I love the 28th one

Several of those look kind of intriguing to me, but I'm more into the scenario as a whole than the individual tentacles used in it. Case in point-
rule34.xxx/index.php?page...d=9443&pid=990#895764