Tricycle

No, he isn't really old enough.  Or quite tall enough, although he's really close.

But he wanted to try.

He'd get up onto the seat, try to walk the tricycle forward, and tip over - head over heels over trike.  Disdaining my help, he'd get back up and do it again.

He could get one foot on a pedal at a time, but then didn't quite get the concept of pushing.

I give it... maybe till mid-summer.