  The Ellis-Bronnikov solution provides a simple toy model for the study of
various aspects of wormhole physics. In this work we solve the Klein-Gordon
equation in this background and find an exact solution in terms of Heun's
function. This may describe 'scalar clouds' ($i.e.$ localized, particle-like
configuration) or scalar waves. However, in the former case, the radial
derivative of the scalar field is discontinuous at the wormhole's throat
(except for the spherical case). This pathology is absent for a suitable scalar
field self-interaction, and we provide evidence for the existence of
spherically symmetric and spinning Q-balls in a Ellis-Bronnikov wormhole
background.
