Marlin And Nemo From Finding Nemo
Most of the fathers on this list are too willing to let their kids get up to shenanigans. Marlin is the exact opposite. He worries over Nemo like a paranoid squirrel with one more nut to last him through winter. It's unhealthy, definitely detrimental to the poor fish's future and extremely funny, especially given the legitimately terrifying sequences Nemo later finds himself in without dad at his side. In some ways, it's bizarre to include these two since they do almost all of their growing apart, but even as they're separated, the personality of and love for the other are what is pushing them to change. Nemo gains a new appreciation for his dad's over-parenting by seeing the horrors of being alone, and Marlin decides to take a half step back after learning how resourceful his son can be without him.