yeah, spaceships are pretty common (fun fact: 2 spaceships were found on the same day including this one in GOL), also in CA it's called a "spaceship". However until now there was no 1D one (1D is also called 1-cell-thick or linear).
Also, you are actually wrong, it is actually much easier to move than to self-synthesize and then remain alive like a replicator. There has been no true replicator found yet in Life as far as I know (arguably, linear propagator may be a replicator) but like millions of spaceships have been found.
can be programmed to self-replicate in any number of ways, but it's so big that it's very hard to simulate it through a full cycle. By contrast, Pavel Grankovskiy's "DOGun SaGaQR"
OK, I didn't know if it was a "true" replicator (what even does "true" mean) so I excluded it. And, running a true replicator from other rule in 0E0P takes millenia, so that leaves DOGun SaGaQR (specifically the QR configuration). Sorry.