READ OUT LOUD. Choose which marked text you prefer to practice with - macrons in verse form, or macrons in prose order, or accent marks in prose order, or focusing on the meter. You will find materials for all of these options below. :-)
VERSE MACRONS. Here is the verse text with macrons:
Regnātorque penūs, mēnsaeque arrōsor herīlis

Queis teneram appōnēns barbam, falsa ossa momordit:

Dēprēnsum et taetrō tenuērunt carcere fūrem,

PROSE MACRONS. Here is the same text with macrons written out in prose word order:
Mūs, et penūs regnātor et mēnsae herīlis arrōsor, ostrea vīdit, lābris summīs hiulca. Queis (quibus) barbam teneram appōnēns, ossa falsa momordit: ast ea, tacta, repente domum clausērunt, et carcere taetrō tenuērunt fūrem dēprēnsum, quī sēmet in tumulum obscūrum dederat.
STRESS (ACCENT) MARKS. Here is the prose text with accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Mus, et penus regnátor et mensae herílis arrósor, óstrea vidit, labris summis hiúlca. Queis (quibus) barbam téneram appónens, ossa falsa momórdit: ast ea, tacta, repénte domum clausérunt, et cárcere taetro tenuérunt furem deprénsum, qui semet in túmulum obscúrum déderat.
ELEGIAC COUPLET METER. Below I have used an interpunct dot · to indicate the metrical elements in each line, and a double line || to indicate the hemistichs of the pentameter line.
Regnā·torque pe·nūs, mēn·saequ~ ar·rōsor he·rīlis

Queis tene·r~ appō·nēns bar·bam, fal·s~ ossa mo·mordit:

Dēprēn·s~ et tae·trō tenu·ērunt· carcere· fūrem,

IMAGE. Here's an illustration for the fable (image source) from a 1539 edition of the emblems:

What follows is an unmarked version of the prose rendering to faciliate word searches: Mus, et penus regnator et mensae herilis arrosor, ostrea vidit, labris summis hiulca. Queis (quibus) barbam teneram apponens, ossa falsa momordit: ast ea, tacta, repente domum clauserunt, et carcere taetro tenuerunt furem deprensum, qui semet in tumulum obscurum dederat.