A thug who elbowed a passing stranger in the face in an unprovoked street attack in Frankston was abusing alcohol and drugs after near-fatal road crash involving a wombat, a court has heard.

Ryan Wells was walking with two companions along a footpath when, without warning or provocation, he viciously attacked a man walking in the opposite direction then smugly grinned as he walked on, about 7.40pm on July 26 last year.

The attack, captured on a CCTV camera, left the victim with a cut lip, bloody nose and bump to the head after he fell to the ground. The man's $2500 dentures were also broken.

Afterwards, he was terrified about contacting police and worried what impact the incident would have on his son, police said.