Below is a walkthrough for the Walk the Stalk side quest in Tiny Tina’s Wonderlands. To obtain this quest, speak with Magic Bean in Overworld after blowing up the ocean.
Pick up magic bean
Pick up the bean.
Place magic bean
Head north to place the magic bean
Flick it
Flick the bean by meleeing it.
Go to Tangledrift
Enter the Tangledrift map transition next to where the bean was.
Investigate the beanstalk
Follow the path forward to reach a house and knock on the door then head inside and speak with Punchfather. Afterwards, follow him outside and continue down the path to find the town. Speak with Punchfather at the entrance to the town then follow him.
Pick up Punchfather
After he transforms, pick him up.
Investigate the lighthouse
Travel to the next objective then place the Punchfather. This will cause a bunch of enemies to spawn. Defeat them then return to the flower in the center of the area. This will cause a mini boss to spawn. Defeat it then pick up the Punchfather.
Investigate the cathedral
Head to the objective to find the cathedral then clear out the enemies inside. Once you’re done, place Punchfather on the flower. Just like before, enemies will spawn. Defeat them.
Investigate the castle
Head the the upper level of the cathedral then slide down the stalk. Work your way forward until you find Punchfather in the last part of the castle. Follow him deeper into the castle to find the flower. When you approach it, enemies will spawn. Defeat them all then speak with Punchfather again.
Enter the parasite’s lair
Follow the objective to the lair and defeat the mushroom boss.
Return to town
After you defeat the boss, take the portal to reach a small island then jump through another portal here to return to town. After Punchfather’s speech, the quest wil complete.