There has been a long and cruel association of deformity with moral monstrosity, so it might be useful to discuss
George Green's "Lord Byron's Foot," which some students will only find funny and some students will find offensive.
Ogden Nash's "The Wendigo," of course.
Robert Graves's "Welsh Incident."
Jack Prelutzky's children's book "The Dragons Are Singing Tonight," illustrated by Peter Sís, has a whole range of takes on dragons.
Stanley Holloway's version of "Sweeney Todd" is another exploration/celebration of human criminality as something fascinatingly monstrous. Stanley Holloway also performed
"With Her Head Tucked Underneath Her Arm," also covered by the Kingston Trio and others.
References to other monster poems, often in translation, are in
this old thread. And
this one (which also shows Chris Childers in all his purple antenna-ed glory).