She, having killed, no more does search,
But on the next green bough to perch,
Where, when he first does lure,
The falcon'r has her sure.
What may not then our Isle presume
While victory his crest does plume!
What may not others fear
If thus he crown each year!
A Caesar he ere long to Gaul,
To Italy an Hannibal,
And to all states not free
Shall climacteric be.
The Pict no shelter now shall find
Within his parti-coloured mind;
But from this valour sad
Shrink underneath the plaid:
Happy if in the tufted brake
The English hunter him mistake,
Nor lay his hounds in near
The Caledonian deer.
But thou, the War's and Fortune's son,
March indefatigably on;
And for the last effect
The Scottish ( Pict ) will not find any shelter from the “English hunter”. These first four lines all contain Scottish themed puns that belittle Scotland in the face of Cromwell’s power. 
 The Scottish hope to be mistaken for an animal as Cromwell hunts for more states to free as was revealed in the previous stanza. Caledonia is the Latin name for the northern part of Scotland, which remained unconquered by the Romans. Marvell presents the English as hounds and the Scottish as deer showing the complete power that Cromwell has over the Scottish.
An Horatian Ode Upon Cromwells Return from Ireland