You know, I'm going to give you this on you first go as it was so close with your "three of a kind" being answer basically.
Yes, (and not many people know this) the word "prial" in playing card parlance is a corruption of Royal Pair and does mean as you say three of a kind, but my connections were much simpler than that with the rest here: -
2/ Blinky (the fish in The Simpsons)
3/ Squeeze Toy Alien (the toy in Toy Story)
4/ Martian Fighting Machine (War of the Worlds)
All being threes of eyes or legs
You know Firkin, you are very good at this and should put together a team to compete on the actual programme. I think it was Kenneth who was talking about doing this, but he disappeared after Aaron slapped his wrist for...................
HOWEVER, here's a harder one (?)