Most Bug-type Pokémon fall into this egg group, making its characteristics similar to that of the Bug-type itself. In this egg group, moves are not passed down as easily, as most base-level Bug Pokémon cannot learn any moves by breeding. There is a notably small amount of Pokémon that are in this group and another, making chain breeding difficult as well.

Pokémon

Only in this egg group

#		Name	Type
010		Caterpie
011		Metapod
012		Butterfree
013		Weedle
014		Kakuna
015		Beedrill
048		Venonat
049		Venomoth
123		Scyther
212		Scizor
165		Ledyba
166		Ledian
167		Spinarak
168		Ariados
193		Yanma
469		Yanmega
204		Pineco
205		Forretress
207		Gligar
472		Gliscor
213		Shuckle
214		Heracross
265		Wurmple
266		Silcoon
267		Beautifly
268		Cascoon
269		Dustox
290		Nincada
291		Ninjask
328		Trapinch
329		Vibrava
330		Flygon
401		Kricketot
402		Kricketune
412		Burmy
413		Wormadam


414		Mothim
415		Combee
416		Vespiquen

In this and another egg group

#	Name	Other
046	Paras	Plant
047	Parasect	Plant
283	Surskit	Water 1
284	Masquerain	Water 1
313	Volbeat	Humanshape
314	Illumise	Humanshape
451	Skorupi	Water 3
452	Drapion	Water 3

Trivia

The Bug egg group is nearly completely exclusive to Bug-type Pokémon, however, it does notably contain several buglike Ground-types and lacks Anorith and Armaldo.
Notably, while Nincada and Ninjask are in this egg group, their relative Shedinja is not. It is instead in the Mineral group for unknown reasons.