B01368/S03 has a 5c/10 replicator formed by a three-cell block:
Unlike many other known replicators, this one turns into an oscillator when stabilized by replicators in adjacent positions in its row. Thus, a single replicator will eventually grow to form a one-dimensional row of copies of itself without gaps. Random patterns in this rule eventually fill the plane with a chaotic grid of interacting vertical and horizontal rows of replicators; when the initial fraction of random live cells is approximately 38%, this grid pattern will be confined within slowly-annealing boundaries between large regions of the plane with the same parity (live replicator cells on dead background in even generations and dead on live in odd generations, or vice versa).
Two parallel replicators can interact to form a breeder that leaves perpendicular trails of replicators behind them, producing a quadratic growth pattern:
The replicator for this rule also forms the basis of this 5c/10 spaceship:
Replicators -- Cellular Automata -- D. Eppstein -- UCI Inf. & Comp. Sci.