It is probably a paralysis tick (Ixodes holocyclus), but I am not good at identifying acarines. This is unfortunate, because I am so good at attracting them. (The same applies to leeches.)
We're looking at the tick from the dorsal side. The mouthparts are buried deep into the side of my knee (which is not normally that red, but I had just scratched it, before noticing the hitchhiker). The eight legs, opaque scutum (shield) and blood filled diverticula of the mid-gut are all visible. Moments later, all parts of the tick were still visible, but as constituent tissues spread out on a piece of kitchen paper.
I don't find tick bites to be much more than an itchy nuisance*, but it's a different story for people who are allergic to tick saliva or who are subjected to numerous tick bites in a short space of time. Many native marsupials are resistant to the effect of paralysis ticks, but flying foxes, which pick up ticks when they feed on low flowers and fruit, and domestic animals are often badly affected.
From the first link:
For the tick's natural hosts, paralysis isn't usually a problem. Bandicoots (the most common host), koalas and other marsupials develop immunity through regular exposure. But less-preferred hosts, such as dogs and cats, often don't get the chance to acquire immunity. An estimated 10-20,000 are paralysed annually, with hundreds dying. Other animals are also affected, including spectacled flying-foxes, a threatened species native to north Queensland, which have died in their thousands.
The Tolga Bat Hospital deals with tick-affected bats by the crate-load.
Here comes summer.
* But I reserve the right to complain loudly and at length about tick bites, no matter how big or small their effect.