No Primeval viewer has really seen the show until they've seen Primarkeval, the Scottish Falsetto Sock Puppet Theatre's hilarous spoof of the series. If you've only seen Season 1 there's a very mild spoiler to a new character in Season 2 but nothing that'll ruin the show for you!
WARNING: there is some bad language in it, mostly due to one of the characters mixing up the two words "Cutter" and "hunter". And some American viewers may struggle with the Scottish accents - I might need to do a transcript for you!
The video is here
All the creatures (both real and invented) appearing in the series are listed here.
(With thanks to Jessica Hall for the link)
The following site has some very funny captioned pictures, but a couple of warnings:
There are some very near-the-knuckle captions on a few of the pictures. You may need to click a button agreeing that you're over 18 before you can enter the site.
Secondly, it's based very much on the superb icanhascheezburger and its sister site ihasahotdog (add a dot com to visit those sites), and many of the captions here echo a lot of their regular themes. If you know these two sites well and are into their humour and "lolspeak", then you might enjoy this Primeval variation on the theme. It's called ihazanomaly.