Relatives

There are some Transformers are relatives throughout the various Transformers continuity. How the concept comes from is ulclear. At least there is yet no unified official explanation.

G1/Beast Era

 * Sideswipe (G1) and Sunstreaker
 * Blaster, Karmen and Toaster
 * Decibel and Legout
 * Fortress Maximus and Grand Maximus in Japanese G1 continuity.
 * Leozack and Lyzack
 * Sixliner and Sixtrain
 * Roulette and Shadow Striker
 * Optimus Prime and Ultra Magnus in Dreamwave G1 continuity.
 * Clamp Down and Deep Cover
 * BW 2 Galvatron and Megastorm
 * DJ, Motor Arm and Gimlet

Car Robot/Robots in Disguise

 * Fire Convoy and God Magnus
 * Wildride, Mach Alert and Speedbreaker
 * Gas Skunk, Guildo and Guushar (Only in the toy catalogs)

Unicron Trilogy

 * Landmine and Landquake
 * Shockblast and Six Shot
 * Superion Maximus and his brother
 * Signal Flare and Offshoot
 * Hardtop and Swindle
 * Undermine and Repugnus

Other relatives

 * Rattrap calls Arcee "Great Ant".
 * Artfire and Fire Convoy are relatives.
 * Bulkhead and Quickstrike are cousins.