  We study pattern formation, fluctuations and scaling induced by a
growth-promoting active walker on an otherwise static interface. Active
particles on an interface define a simple model for energy consuming proteins
embedded in the plasma membrane, responsible for membrane deformation and cell
movement. In our model, the active particle overturns local valleys of the
interface into hills, simulating growth, while itself sliding and seeking new
valleys. In 1D, this overturn-slide-search dynamics of the active particle
causes it to move superdiffusively in the transverse direction while pulling
the immobile interface upwards. Using Monte Carlo simulations, we find an
emerging tent-like mean profile developing with time, despite large
fluctuations. The roughness of the interface follows scaling with the growth,
dynamic and roughness exponents, derived using simple arguments as $\beta=2/3,
z=3/2, \alpha=1/2$ respectively, implying a breakdown of the usual scaling law
$\beta = \alpha/z$, owing to very local growth of the interface. The transverse
displacement of the puller on the interface scales as $\sim t^{2/3}$ and the
probability distribution of its displacement is bimodal, with an unusual linear
cusp at the origin. Both the mean interface pattern and probability
distribution display scaling. A puller on a static 2D interface also displays
aspects of scaling in the mean profile and probability distribution. We also
show that a pusher on a fluctuating interface moves subdiffusively leading to a
separation of time scale in pusher motion and interface response.
