Very minor error, but an error none the less. This mob is tagged as just a regular mob and not an animal:
[Thu Aug 25 00:29:47 2011] Targeted (NPC): a ferocious hammerhead
[Thu Aug 25 00:29:55 2011] You begin casting Engulfing Roots.
[Thu Aug 25 00:29:57 2011] You regain your concentration and continue your casting.
[Thu Aug 25 00:29:57 2011] a ferocious hammerhead was hit by non-melee for 175 points of damage.
[Thu Aug 25 00:29:57 2011] A ferocious hammerhead's feet become entwined.
[Thu Aug 25 00:30:00 2011] This spell only works on animals.
[Thu Aug 25 00:30:00 2011] This spell only works on animals.
[Thu Aug 25 00:30:00 2011] This spell only works on animals.
[Thu Aug 25 00:30:00 2011] This spell only works on animals.
[Thu Aug 25 00:30:01 2011] This spell only works on animals.
[Thu Aug 25 00:30:01 2011] This spell only works on animals.
[Thu Aug 25 00:30:02 2011] This spell only works on animals.
[Thu Aug 25 00:30:02 2011] This spell only works on animals.
Which shows me targetting, getting a root off then being like "WTF why can't I animal tash this guy".
He is tagged as an animal here:
http://eqbeastiary.allakhazam.com/search.shtml?id=18253