Pushover Smurf appears in the episode The smurf who couldn't say no.
All of the smurfs asked Pushover to do their work because he never said no to them. When Scaredy had to go to the Great Swamp to get the foxfire, he went to Pushover's house to asking to do it on his place.
Pushover got the foxfire from the Great Swamp, but he accidentally put the fire out. A creature rose from the swamp growling, and saying "Curses he who killed the flame. Curses he who gives me pain". Meanwile in the village, Scaredy learnt about what happens if the foxfire went out. Papa Smurf told Scaredy that it would awaken the Marshmonster. Scaredy does find Pushover, and both of them ran back to the village with the foxfire.
Pushover and Scaredy return to the village, and the firefly lantern that was set up earlier gets lite. This dangerous experience teaches Pushover that he must sometimes say no.