Original part on my Toro looks like the first picture, all steel cap. These have two contact points. The ones like the second picture with the plastic cap found on kids ride on cars and etc. seem to grab better because they have four or more contact points and can be driven on with a 3/4" (19mm) socket.
Toro 8/24 (38080) 1989
Toro 421-QZE (38585) 2008 (Gone)
Toro 721-QZR (38741) 2015 (Hemi Predator Power)
Experience is something you don't get until just after you need it.