Show Last Comment for an Issue

import com.atlassian.jira.component.ComponentAccessor

def comments = issue.comments
if (comments) {
    def rendererManager = ComponentAccessor.getRendererManager()
    def fieldLayoutManager = ComponentAccessor.getFieldLayoutManager()
    def fieldLayoutItem = fieldLayoutManager.getFieldLayout(issue).getFieldLayoutItem('comment')
    def renderer = rendererManager.getRendererForField(fieldLayoutItem)
    renderer.render(comments.last().body, null)
}