Enter academia with no undergraduate degree (only professional experience)
I'm sure it varies by country, but in the US you would not have a good chance of getting an academic position. 

However, you might find a position at an academic institution as an OPS (other personnel service), which is considered equivalent to a "contractor" position with no benefits and hourly wages. 

I'm by no means a degree snob, but getting a degree is akin to getting a ticket to an event. If you don't have one, though shall not pass..