Something

LoadMIBs: /usr/share/snmp/mibs/UCD-SNMP-MIB.txt
Target[localhost.cpu]:`/usr/bin/awk '/cpu /{print $2+$3; print $2+$3+$4; print "quite some time"; print "domain.com"}'</proc/stat` ssCpuRawNice.0&ssCpuRawNice.0:public@localhost
RouterUptime[localhost.cpu]: public@localhost
MaxBytes[localhost.cpu]: 100
Title[localhost.cpu]: CPU Load
PageTop[localhost.cpu]: <H1>Active CPU Load %</H1>
Unscaled[localhost.cpu]: ymwd
ShortLegend[localhost.cpu]: %
YLegend[localhost.cpu]: CPU Utilization
Legend1[localhost.cpu]: Active CPU in % (Load)
Legend2[localhost.cpu]:
Legend3[localhost.cpu]:
Legend4[localhost.cpu]:
LegendI[localhost.cpu]:  Active
LegendO[localhost.cpu]:
Options[localhost.cpu]: growright,nopercent,gauge

LoadMIBs: /usr/share/snmp/mibs/HOST-RESOURCES-MIB.txt
Target[localhost.mem]:`free -bt | grep buffers\/cache | awk '{print $3"\n"$4}'`
Target[localhost.mem]: ( memAvailReal.0&memAvailReal.0:public@localhost ) * 100 / ( memTotalReal.0&memTotalReal.0:public@localhost )
PageTop[localhost.mem]: <H1>Free Memory</H1>
Options[localhost.mem]: nopercent,growright,gauge,noinfo
Title[localhost.mem]: Free Memory
MaxBytes[localhost.mem]: 1000000
kMG[localhost.mem]: k,M,G,T,P,X
YLegend[localhost.mem]: bytes
ShortLegend[localhost.mem]: bytes
LegendI[localhost.mem]:  Free Memory:
LegendO[localhost.mem]:
Legend1[localhost.mem]: Free memory, not including swap, in bytes

Target[localhost.load]: `/etc/mrtg/system load`
Title[localhost.load]: Load Averages (x 100)
PageTop[localhost.load]: <h3>Load Averages</h3>
YLegend[localhost.load]: Load Averages
ShortLegend[localhost.load]: &nbsp;&nbsp;&nbsp;
LegendI[localhost.load]: 5-minute Load&nbsp;
LegendO[localhost.load]: 15-mintute Load&nbsp;