Apart form the SNMP plugins from the Nagios Plugin package, the Nagios community provides a large variety of other plugins for special purposes. Most of them can be found at
http://www.nagiosexchange.org/ in the category
Check Plugins | SNMP.
One of these is the package
nagios-snmp-plugins, which exists not only as source code but also as an RPM package (for Red Hat and Fedora). It contains two very easy-to-use plugins:
Both absolutely require the NET-SNMP agent as the partner on the other side (see 11.2.2 The NET-SNMP daemon from page 238) and use
ucdavis.prTable to test the processes ...