Had a bit of a search and it would appear it is criminal damage of property due to being a tamed animal
'Property
The definition of property for the purposes of criminal damage is found in s.10(1) Criminal Damage Act 1971. Property embraces only tangible property. It includes real property...
That appears a bit odd to me (not punching a Palace Eagle), but it being attempted criminal damage. I have always thought of criminal damage as being against an inanimate object such as a wall or bus stop.
Surely there is some form of actual crime category for it being against an animal?