ConwayLife.com

... as seen in cow . x = 17, y = 14, rule = B3/S23 15b2o$14bobo$12b3o$11bo3bo$11bo2b2o$9b2o$8bo$8bo$6b2o$2o3bo$obo2bo$2b 3o$bo$b2o! It can also be siamized to a house , yielding the smallest still life involving houses ( house siamese shillelagh ).

... count and bounding box it's tied with spiral ) Smallest still life composed entirely of pentominoes Smallest still life that is a chain of four siamized smaller still lifes Smallest still life that completely encloses a 3×3 patch of empty cells (equivalently: an empty cell with no neighbors).

... you want some sort of a taxonomy here, the two "versions" on the L & R seem to actually include a cis fuse with two tails , as a basic component, siamized with either a copy of itself or with an eater 1 (in the same way the elevener is a type of siamese eater-1s).